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3749 commits

Author SHA1 Message Date
Eric Dumazet
5579ee462d net_sched: export pfifo_fast prio2band[]
pfifo_fast prio2band[] is renamed to sch_default_prio2band[]
and exported because we want to share it in FQ.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Dave Taht <dave.taht@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-10-05 13:27:31 +02:00
Eric Dumazet
2ae45136a9 net_sched: sch_fq: remove q->ktime_cache
Now that both enqueue() and dequeue() need to use ktime_get_ns(),
there is no point wasting 8 bytes in struct fq_sched_data.

This makes room for future fields. ;)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Dave Taht <dave.taht@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-10-05 13:27:20 +02:00
Eric Dumazet
28b24f9002 net: implement lockless SO_MAX_PACING_RATE
SO_MAX_PACING_RATE setsockopt() does not need to hold
the socket lock, because sk->sk_pacing_rate readers
can run fine if the value is changed by other threads,
after adding READ_ONCE() accessors.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:09:54 +01:00
Eric Dumazet
10bbf1652c net: implement lockless SO_PRIORITY
This is a followup of 8bf43be799 ("net: annotate data-races
around sk->sk_priority").

sk->sk_priority can be read and written without holding the socket lock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:09:54 +01:00
Eric Dumazet
8f6c4ff9e0 net_sched: sch_fq: always garbage collect
FQ performs garbage collection at enqueue time, and only
if number of flows is above a given threshold, which
is hit after the qdisc has been used a bit.

Since an RB-tree traversal is needed to locate a flow,
it makes sense to perform gc all the time, to keep
rb-trees smaller.

This reduces by 50 % average storage costs in FQ,
and avoids 1 cache line miss at enqueue time when
fast path added in prior patch can not be used.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 13:20:36 +01:00
Eric Dumazet
076433bd78 net_sched: sch_fq: add fast path for mostly idle qdisc
TCQ_F_CAN_BYPASS can be used by few qdiscs.

Idea is that if we queue a packet to an empty qdisc,
following dequeue() would pick it immediately.

FQ can not use the generic TCQ_F_CAN_BYPASS code,
because some additional checks need to be performed.

This patch adds a similar fast path to FQ.

Most of the time, qdisc is not throttled,
and many packets can avoid bringing/touching
at least four cache lines, and consuming 128bytes
of memory to store the state of a flow.

After this patch, netperf can send UDP packets about 13 % faster,
and pktgen goes 30 % faster (when FQ is in the way), on a fast NIC.

TCP traffic is also improved, thanks to a reduction of cache line misses.
I have measured a 5 % increase of throughput on a tcp_rr intensive workload.

tc -s -d qd sh dev eth1
...
qdisc fq 8004: parent 1:2 limit 10000p flow_limit 100p buckets 1024
   orphan_mask 1023 quantum 3028b initial_quantum 15140b low_rate_threshold 550Kbit
   refill_delay 40ms timer_slack 10us horizon 10s horizon_drop
 Sent 5646784384 bytes 1985161 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
  flows 122 (inactive 122 throttled 0)
  gc 0 highprio 0 fastpath 659990 throttled 27762 latency 8.57us

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 13:20:36 +01:00
Eric Dumazet
ee9af4e14d net_sched: sch_fq: change how @inactive is tracked
Currently, when one fq qdisc has no more packets to send, it can still
have some flows stored in its RR lists (q->new_flows & q->old_flows)

This was a design choice, but what is a bit disturbing is that
the inactive_flows counter does not include the count of empty flows
in RR lists.

As next patch needs to know better if there are active flows,
this change makes inactive_flows exact.

Before the patch, following command on an empty qdisc could have returned:

lpaa17:~# tc -s -d qd sh dev eth1 | grep inactive
  flows 1322 (inactive 1316 throttled 0)
  flows 1330 (inactive 1325 throttled 0)
  flows 1193 (inactive 1190 throttled 0)
  flows 1208 (inactive 1202 throttled 0)

After the patch, we now have:

lpaa17:~# tc -s -d qd sh dev eth1 | grep inactive
  flows 1322 (inactive 1322 throttled 0)
  flows 1330 (inactive 1330 throttled 0)
  flows 1193 (inactive 1193 throttled 0)
  flows 1208 (inactive 1208 throttled 0)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 13:20:36 +01:00
Eric Dumazet
54ff8ad69c net_sched: sch_fq: struct sched_data reorg
q->flows can be often modified, and q->timer_slack is read mostly.

Exchange the two fields, so that cache line countaining
quantum, initial_quantum, and other critical parameters
stay clean (read-mostly).

Move q->watchdog next to q->stat_throttled

Add comments explaining how the structure is split in
three different parts.

pahole output before the patch:

struct fq_sched_data {
	struct fq_flow_head        new_flows;            /*     0  0x10 */
	struct fq_flow_head        old_flows;            /*  0x10  0x10 */
	struct rb_root             delayed;              /*  0x20   0x8 */
	u64                        time_next_delayed_flow; /*  0x28   0x8 */
	u64                        ktime_cache;          /*  0x30   0x8 */
	unsigned long              unthrottle_latency_ns; /*  0x38   0x8 */
	/* --- cacheline 1 boundary (64 bytes) --- */
	struct fq_flow             internal __attribute__((__aligned__(64))); /*  0x40  0x80 */

	/* XXX last struct has 16 bytes of padding */

	/* --- cacheline 3 boundary (192 bytes) --- */
	u32                        quantum;              /*  0xc0   0x4 */
	u32                        initial_quantum;      /*  0xc4   0x4 */
	u32                        flow_refill_delay;    /*  0xc8   0x4 */
	u32                        flow_plimit;          /*  0xcc   0x4 */
	unsigned long              flow_max_rate;        /*  0xd0   0x8 */
	u64                        ce_threshold;         /*  0xd8   0x8 */
	u64                        horizon;              /*  0xe0   0x8 */
	u32                        orphan_mask;          /*  0xe8   0x4 */
	u32                        low_rate_threshold;   /*  0xec   0x4 */
	struct rb_root *           fq_root;              /*  0xf0   0x8 */
	u8                         rate_enable;          /*  0xf8   0x1 */
	u8                         fq_trees_log;         /*  0xf9   0x1 */
	u8                         horizon_drop;         /*  0xfa   0x1 */

	/* XXX 1 byte hole, try to pack */

<bad>	u32                        flows;                /*  0xfc   0x4 */
	/* --- cacheline 4 boundary (256 bytes) --- */
	u32                        inactive_flows;       /* 0x100   0x4 */
	u32                        throttled_flows;      /* 0x104   0x4 */
	u64                        stat_gc_flows;        /* 0x108   0x8 */
	u64                        stat_internal_packets; /* 0x110   0x8 */
	u64                        stat_throttled;       /* 0x118   0x8 */
	u64                        stat_ce_mark;         /* 0x120   0x8 */
	u64                        stat_horizon_drops;   /* 0x128   0x8 */
	u64                        stat_horizon_caps;    /* 0x130   0x8 */
	u64                        stat_flows_plimit;    /* 0x138   0x8 */
	/* --- cacheline 5 boundary (320 bytes) --- */
	u64                        stat_pkts_too_long;   /* 0x140   0x8 */
	u64                        stat_allocation_errors; /* 0x148   0x8 */
<bad>	u32                        timer_slack;          /* 0x150   0x4 */

	/* XXX 4 bytes hole, try to pack */

	struct qdisc_watchdog      watchdog;             /* 0x158  0x48 */

	/* size: 448, cachelines: 7, members: 34 */
	/* sum members: 411, holes: 2, sum holes: 5 */
	/* padding: 32 */
	/* paddings: 1, sum paddings: 16 */
	/* forced alignments: 1 */
};

pahole output after the patch:

struct fq_sched_data {
	struct fq_flow_head        new_flows;            /*     0  0x10 */
	struct fq_flow_head        old_flows;            /*  0x10  0x10 */
	struct rb_root             delayed;              /*  0x20   0x8 */
	u64                        time_next_delayed_flow; /*  0x28   0x8 */
	u64                        ktime_cache;          /*  0x30   0x8 */
	unsigned long              unthrottle_latency_ns; /*  0x38   0x8 */
	/* --- cacheline 1 boundary (64 bytes) --- */
	struct fq_flow             internal __attribute__((__aligned__(64))); /*  0x40  0x80 */

	/* XXX last struct has 16 bytes of padding */

	/* --- cacheline 3 boundary (192 bytes) --- */
	u32                        quantum;              /*  0xc0   0x4 */
	u32                        initial_quantum;      /*  0xc4   0x4 */
	u32                        flow_refill_delay;    /*  0xc8   0x4 */
	u32                        flow_plimit;          /*  0xcc   0x4 */
	unsigned long              flow_max_rate;        /*  0xd0   0x8 */
	u64                        ce_threshold;         /*  0xd8   0x8 */
	u64                        horizon;              /*  0xe0   0x8 */
	u32                        orphan_mask;          /*  0xe8   0x4 */
	u32                        low_rate_threshold;   /*  0xec   0x4 */
	struct rb_root *           fq_root;              /*  0xf0   0x8 */
	u8                         rate_enable;          /*  0xf8   0x1 */
	u8                         fq_trees_log;         /*  0xf9   0x1 */
	u8                         horizon_drop;         /*  0xfa   0x1 */

	/* XXX 1 byte hole, try to pack */

<good>	u32                        timer_slack;          /*  0xfc   0x4 */
	/* --- cacheline 4 boundary (256 bytes) --- */
<good>	u32                        flows;                /* 0x100   0x4 */
	u32                        inactive_flows;       /* 0x104   0x4 */
	u32                        throttled_flows;      /* 0x108   0x4 */

	/* XXX 4 bytes hole, try to pack */

	u64                        stat_throttled;       /* 0x110   0x8 */
<better> struct qdisc_watchdog     watchdog;             /* 0x118  0x48 */
	/* --- cacheline 5 boundary (320 bytes) was 32 bytes ago --- */
	u64                        stat_gc_flows;        /* 0x160   0x8 */
	u64                        stat_internal_packets; /* 0x168   0x8 */
	u64                        stat_ce_mark;         /* 0x170   0x8 */
	u64                        stat_horizon_drops;   /* 0x178   0x8 */
	/* --- cacheline 6 boundary (384 bytes) --- */
	u64                        stat_horizon_caps;    /* 0x180   0x8 */
	u64                        stat_flows_plimit;    /* 0x188   0x8 */
	u64                        stat_pkts_too_long;   /* 0x190   0x8 */
	u64                        stat_allocation_errors; /* 0x198   0x8 */

	/* Force padding: */
	u64                        :64;
	u64                        :64;
	u64                        :64;
	u64                        :64;

	/* size: 448, cachelines: 7, members: 34 */
	/* sum members: 411, holes: 2, sum holes: 5 */
	/* padding: 32 */
	/* paddings: 1, sum paddings: 16 */
	/* forced alignments: 1 */
};

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 13:20:36 +01:00
Pedro Tammela
ef765c2587 net/sched: cls_route: make netlink errors meaningful
Use netlink extended ack and parsing policies to return more meaningful
errors instead of the relying solely on errnos.

Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-13 12:38:52 +01:00
Zhengchao Shao
762c8dc7f2 net: dst: remove unnecessary input parameter in dst_alloc and dst_init
Since commit 1202cdd66531("Remove DECnet support from kernel") has been
merged, all callers pass in the initial_ref value of 1 when they call
dst_alloc(). Therefore, remove initial_ref when the dst_alloc() is
declared and replace initial_ref with 1 in dst_alloc().
Also when all callers call dst_init(), the value of initial_ref is 1.
Therefore, remove the input parameter initial_ref of the dst_init() and
replace initial_ref with the value 1 in dst_init.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Link: https://lore.kernel.org/r/20230911125045.346390-1-shaozhengchao@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-09-12 11:42:25 +02:00
valis
8fc134fee2 net: sched: sch_qfq: Fix UAF in qfq_dequeue()
When the plug qdisc is used as a class of the qfq qdisc it could trigger a
UAF. This issue can be reproduced with following commands:

  tc qdisc add dev lo root handle 1: qfq
  tc class add dev lo parent 1: classid 1:1 qfq weight 1 maxpkt 512
  tc qdisc add dev lo parent 1:1 handle 2: plug
  tc filter add dev lo parent 1: basic classid 1:1
  ping -c1 127.0.0.1

and boom:

[  285.353793] BUG: KASAN: slab-use-after-free in qfq_dequeue+0xa7/0x7f0
[  285.354910] Read of size 4 at addr ffff8880bad312a8 by task ping/144
[  285.355903]
[  285.356165] CPU: 1 PID: 144 Comm: ping Not tainted 6.5.0-rc3+ #4
[  285.357112] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[  285.358376] Call Trace:
[  285.358773]  <IRQ>
[  285.359109]  dump_stack_lvl+0x44/0x60
[  285.359708]  print_address_description.constprop.0+0x2c/0x3c0
[  285.360611]  kasan_report+0x10c/0x120
[  285.361195]  ? qfq_dequeue+0xa7/0x7f0
[  285.361780]  qfq_dequeue+0xa7/0x7f0
[  285.362342]  __qdisc_run+0xf1/0x970
[  285.362903]  net_tx_action+0x28e/0x460
[  285.363502]  __do_softirq+0x11b/0x3de
[  285.364097]  do_softirq.part.0+0x72/0x90
[  285.364721]  </IRQ>
[  285.365072]  <TASK>
[  285.365422]  __local_bh_enable_ip+0x77/0x90
[  285.366079]  __dev_queue_xmit+0x95f/0x1550
[  285.366732]  ? __pfx_csum_and_copy_from_iter+0x10/0x10
[  285.367526]  ? __pfx___dev_queue_xmit+0x10/0x10
[  285.368259]  ? __build_skb_around+0x129/0x190
[  285.368960]  ? ip_generic_getfrag+0x12c/0x170
[  285.369653]  ? __pfx_ip_generic_getfrag+0x10/0x10
[  285.370390]  ? csum_partial+0x8/0x20
[  285.370961]  ? raw_getfrag+0xe5/0x140
[  285.371559]  ip_finish_output2+0x539/0xa40
[  285.372222]  ? __pfx_ip_finish_output2+0x10/0x10
[  285.372954]  ip_output+0x113/0x1e0
[  285.373512]  ? __pfx_ip_output+0x10/0x10
[  285.374130]  ? icmp_out_count+0x49/0x60
[  285.374739]  ? __pfx_ip_finish_output+0x10/0x10
[  285.375457]  ip_push_pending_frames+0xf3/0x100
[  285.376173]  raw_sendmsg+0xef5/0x12d0
[  285.376760]  ? do_syscall_64+0x40/0x90
[  285.377359]  ? __static_call_text_end+0x136578/0x136578
[  285.378173]  ? do_syscall_64+0x40/0x90
[  285.378772]  ? kasan_enable_current+0x11/0x20
[  285.379469]  ? __pfx_raw_sendmsg+0x10/0x10
[  285.380137]  ? __sock_create+0x13e/0x270
[  285.380673]  ? __sys_socket+0xf3/0x180
[  285.381174]  ? __x64_sys_socket+0x3d/0x50
[  285.381725]  ? entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.382425]  ? __rcu_read_unlock+0x48/0x70
[  285.382975]  ? ip4_datagram_release_cb+0xd8/0x380
[  285.383608]  ? __pfx_ip4_datagram_release_cb+0x10/0x10
[  285.384295]  ? preempt_count_sub+0x14/0xc0
[  285.384844]  ? __list_del_entry_valid+0x76/0x140
[  285.385467]  ? _raw_spin_lock_bh+0x87/0xe0
[  285.386014]  ? __pfx__raw_spin_lock_bh+0x10/0x10
[  285.386645]  ? release_sock+0xa0/0xd0
[  285.387148]  ? preempt_count_sub+0x14/0xc0
[  285.387712]  ? freeze_secondary_cpus+0x348/0x3c0
[  285.388341]  ? aa_sk_perm+0x177/0x390
[  285.388856]  ? __pfx_aa_sk_perm+0x10/0x10
[  285.389441]  ? check_stack_object+0x22/0x70
[  285.390032]  ? inet_send_prepare+0x2f/0x120
[  285.390603]  ? __pfx_inet_sendmsg+0x10/0x10
[  285.391172]  sock_sendmsg+0xcc/0xe0
[  285.391667]  __sys_sendto+0x190/0x230
[  285.392168]  ? __pfx___sys_sendto+0x10/0x10
[  285.392727]  ? kvm_clock_get_cycles+0x14/0x30
[  285.393328]  ? set_normalized_timespec64+0x57/0x70
[  285.393980]  ? _raw_spin_unlock_irq+0x1b/0x40
[  285.394578]  ? __x64_sys_clock_gettime+0x11c/0x160
[  285.395225]  ? __pfx___x64_sys_clock_gettime+0x10/0x10
[  285.395908]  ? _copy_to_user+0x3e/0x60
[  285.396432]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.397086]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.397734]  ? do_syscall_64+0x71/0x90
[  285.398258]  __x64_sys_sendto+0x74/0x90
[  285.398786]  do_syscall_64+0x64/0x90
[  285.399273]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.399949]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.400605]  ? do_syscall_64+0x71/0x90
[  285.401124]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.401807] RIP: 0033:0x495726
[  285.402233] Code: ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 2c 00 00 00 0f 09
[  285.404683] RSP: 002b:00007ffcc25fb618 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[  285.405677] RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 0000000000495726
[  285.406628] RDX: 0000000000000040 RSI: 0000000002518750 RDI: 0000000000000000
[  285.407565] RBP: 00000000005205ef R08: 00000000005f8838 R09: 000000000000001c
[  285.408523] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000002517634
[  285.409460] R13: 00007ffcc25fb6f0 R14: 0000000000000003 R15: 0000000000000000
[  285.410403]  </TASK>
[  285.410704]
[  285.410929] Allocated by task 144:
[  285.411402]  kasan_save_stack+0x1e/0x40
[  285.411926]  kasan_set_track+0x21/0x30
[  285.412442]  __kasan_slab_alloc+0x55/0x70
[  285.412973]  kmem_cache_alloc_node+0x187/0x3d0
[  285.413567]  __alloc_skb+0x1b4/0x230
[  285.414060]  __ip_append_data+0x17f7/0x1b60
[  285.414633]  ip_append_data+0x97/0xf0
[  285.415144]  raw_sendmsg+0x5a8/0x12d0
[  285.415640]  sock_sendmsg+0xcc/0xe0
[  285.416117]  __sys_sendto+0x190/0x230
[  285.416626]  __x64_sys_sendto+0x74/0x90
[  285.417145]  do_syscall_64+0x64/0x90
[  285.417624]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.418306]
[  285.418531] Freed by task 144:
[  285.418960]  kasan_save_stack+0x1e/0x40
[  285.419469]  kasan_set_track+0x21/0x30
[  285.419988]  kasan_save_free_info+0x27/0x40
[  285.420556]  ____kasan_slab_free+0x109/0x1a0
[  285.421146]  kmem_cache_free+0x1c2/0x450
[  285.421680]  __netif_receive_skb_core+0x2ce/0x1870
[  285.422333]  __netif_receive_skb_one_core+0x97/0x140
[  285.423003]  process_backlog+0x100/0x2f0
[  285.423537]  __napi_poll+0x5c/0x2d0
[  285.424023]  net_rx_action+0x2be/0x560
[  285.424510]  __do_softirq+0x11b/0x3de
[  285.425034]
[  285.425254] The buggy address belongs to the object at ffff8880bad31280
[  285.425254]  which belongs to the cache skbuff_head_cache of size 224
[  285.426993] The buggy address is located 40 bytes inside of
[  285.426993]  freed 224-byte region [ffff8880bad31280, ffff8880bad31360)
[  285.428572]
[  285.428798] The buggy address belongs to the physical page:
[  285.429540] page:00000000f4b77674 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbad31
[  285.430758] flags: 0x100000000000200(slab|node=0|zone=1)
[  285.431447] page_type: 0xffffffff()
[  285.431934] raw: 0100000000000200 ffff88810094a8c0 dead000000000122 0000000000000000
[  285.432757] raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
[  285.433562] page dumped because: kasan: bad access detected
[  285.434144]
[  285.434320] Memory state around the buggy address:
[  285.434828]  ffff8880bad31180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.435580]  ffff8880bad31200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.436264] >ffff8880bad31280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  285.436777]                                   ^
[  285.437106]  ffff8880bad31300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
[  285.437616]  ffff8880bad31380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.438126] ==================================================================
[  285.438662] Disabling lock debugging due to kernel taint

Fix this by:
1. Changing sch_plug's .peek handler to qdisc_peek_dequeued(), a
function compatible with non-work-conserving qdiscs
2. Checking the return value of qdisc_dequeue_peeked() in sch_qfq.

Fixes: 462dbc9101 ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Reported-by: valis <sec@valis.email>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230901162237.11525-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-09-05 08:54:12 +02:00
Eric Dumazet
8c21ab1bae net/sched: fq_pie: avoid stalls in fq_pie_timer()
When setting a high number of flows (limit being 65536),
fq_pie_timer() is currently using too much time as syzbot reported.

Add logic to yield the cpu every 2048 flows (less than 150 usec
on debug kernels).
It should also help by not blocking qdisc fast paths for too long.
Worst case (65536 flows) would need 31 jiffies for a complete scan.

Relevant extract from syzbot report:

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2663 jiffies s: 873 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5177 Comm: syz-executor273 Not tainted 6.5.0-syzkaller-00453-g727dbda16b83 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:236
Code: 2e 0f 1f 84 00 00 00 00 00 65 8b 05 01 b2 7d 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 <a9> 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 85 c0 74 4f 8b
RSP: 0018:ffffc90000007bb8 EFLAGS: 00000206
RAX: 0000000000000101 RBX: ffffc9000dc0d140 RCX: ffffffff885893b0
RDX: ffff88807c075940 RSI: 0000000000000100 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000dc0d178
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000555555d54380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b442f6130 CR3: 000000006fe1c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 pie_calculate_probability+0x480/0x850 net/sched/sch_pie.c:415
 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387
 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700

Fixes: ec97ecf1eb ("net: sched: add Flow Queue PIE packet scheduler")
Link: https://lore.kernel.org/lkml/00000000000017ad3f06040bf394@google.com/
Reported-by: syzbot+e46fbd5289363464bc13@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230829123541.3745013-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-31 11:21:52 +02:00
Paolo Abeni
c873512ef3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in late fixes to prepare for the 6.6 net-next PR.

No conflicts.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-29 07:44:56 +02:00
Budimir Markovic
b3d26c5702 net/sched: sch_hfsc: Ensure inner classes have fsc curve
HFSC assumes that inner classes have an fsc curve, but it is currently
possible for classes without an fsc curve to become parents. This leads
to bugs including a use-after-free.

Don't allow non-root classes without HFSC_FSC to become parents.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Budimir Markovic <markovicbudimir@gmail.com>
Signed-off-by: Budimir Markovic <markovicbudimir@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230824084905.422-1-markovicbudimir@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-25 18:57:54 -07:00
Jakub Kicinski
57ce6427e0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

include/net/inet_sock.h
  f866fbc842 ("ipv4: fix data-races around inet->inet_id")
  c274af2242 ("inet: introduce inet->inet_flags")
https://lore.kernel.org/all/679ddff6-db6e-4ff6-b177-574e90d0103d@tessares.net/

Adjacent changes:

drivers/net/bonding/bond_alb.c
  e74216b8de ("bonding: fix macvlan over alb bond support")
  f11e5bd159 ("bonding: support balance-alb with openvswitch")

drivers/net/ethernet/broadcom/bgmac.c
  d6499f0b7c ("net: bgmac: Return PTR_ERR() for fixed_phy_register()")
  23a14488ea ("net: bgmac: Fix return value check for fixed_phy_register()")

drivers/net/ethernet/broadcom/genet/bcmmii.c
  32bbe64a13 ("net: bcmgenet: Fix return value check for fixed_phy_register()")
  acf50d1adb ("net: bcmgenet: Return PTR_ERR() for fixed_phy_register()")

net/sctp/socket.c
  f866fbc842 ("ipv4: fix data-races around inet->inet_id")
  b09bde5c35 ("inet: move inet->mc_loop to inet->inet_frags")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-24 10:51:39 -07:00
Jamal Hadi Salim
da71714e35 net/sched: fix a qdisc modification with ambiguous command request
When replacing an existing root qdisc, with one that is of the same kind, the
request boils down to essentially a parameterization change  i.e not one that
requires allocation and grafting of a new qdisc. syzbot was able to create a
scenario which resulted in a taprio qdisc replacing an existing taprio qdisc
with a combination of NLM_F_CREATE, NLM_F_REPLACE and NLM_F_EXCL leading to
create and graft scenario.
The fix ensures that only when the qdisc kinds are different that we should
allow a create and graft, otherwise it goes into the "change" codepath.

While at it, fix the code and comments to improve readability.

While syzbot was able to create the issue, it did not zone on the root cause.
Analysis from Vladimir Oltean <vladimir.oltean@nxp.com> helped narrow it down.

v1->V2 changes:
- remove "inline" function definition (Vladmir)
- remove extrenous braces in branches (Vladmir)
- change inline function names (Pedro)
- Run tdc tests (Victor)
v2->v3 changes:
- dont break else/if (Simon)

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+a3618a167af2021433cd@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/20230816225759.g25x76kmgzya2gei@skbuf/T/
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-23 09:44:48 +01:00
Eric Dumazet
bc1fb82ae1 net: annotate data-races around sk->sk_lingertime
sk_getsockopt() runs locklessly. This means sk->sk_lingertime
can be read while other threads are changing its value.

Other reads also happen without socket lock being held,
and must be annotated.

Remove preprocessor logic using BITS_PER_LONG, compilers
are smart enough to figure this by themselves.

v2: fixed a clang W=1 (-Wtautological-constant-out-of-range-compare) warning
    (Jakub)

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-21 07:41:57 +01:00
François Michel
3cad70bc74 netem: use seeded PRNG for correlated loss events
Use prandom_u32_state() instead of get_random_u32() to generate
the correlated loss events of netem.

Signed-off-by: François Michel <francois.michel@uclouvain.be>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://lore.kernel.org/r/20230815092348.1449179-4-francois.michel@uclouvain.be
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-17 19:15:06 -07:00
François Michel
9c87b2aecc netem: use a seeded PRNG for generating random losses
Use prandom_u32_state() instead of get_random_u32() to generate
the random loss events of netem. The state of the prng is part
of the prng attribute of struct netem_sched_data.

Signed-off-by: François Michel <francois.michel@uclouvain.be>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://lore.kernel.org/r/20230815092348.1449179-3-francois.michel@uclouvain.be
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-17 19:15:05 -07:00
François Michel
4072d97ddc netem: add prng attribute to netem_sched_data
Add prng attribute to struct netem_sched_data and
allows setting the seed of the PRNG through netlink
using the new TCA_NETEM_PRNG_SEED attribute.
The PRNG attribute is not actually used yet.

Signed-off-by: François Michel <francois.michel@uclouvain.be>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://lore.kernel.org/r/20230815092348.1449179-2-francois.michel@uclouvain.be
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-17 19:15:05 -07:00
Vladimir Oltean
665338b2a7 net/sched: taprio: dump class stats for the actual q->qdiscs[]
This makes a difference for the software scheduling mode, where
dev_queue->qdisc_sleeping is the same as the taprio root Qdisc itself,
but when we're talking about what Qdisc and stats get reported for a
traffic class, the root taprio isn't what comes to mind, but q->qdiscs[]
is.

To understand the difference, I've attempted to send 100 packets in
software mode through class 8001:5, and recorded the stats before and
after the change.

Here is before:

$ tc -s class show dev eth0
class taprio 8001:1 root leaf 8001:
 Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:2 root leaf 8001:
 Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:3 root leaf 8001:
 Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:4 root leaf 8001:
 Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:5 root leaf 8001:
 Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:6 root leaf 8001:
 Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:7 root leaf 8001:
 Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:8 root leaf 8001:
 Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0

and here is after:

class taprio 8001:1 root
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:2 root
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:3 root
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:4 root
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:5 root
 Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:6 root
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:7 root
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0
class taprio 8001:8 root leaf 800d:
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0
 window_drops 0

The most glaring (and expected) difference is that before, all class
stats reported the global stats, whereas now, they really report just
the counters for that traffic class.

Finally, Pedro Tammela points out that there is a tc selftest which
checks specifically which handle do the child Qdiscs corresponding to
each class have. That's changing here - taprio no longer reports
tcm->tcm_info as the same handle "1:" as itself (the root Qdisc), but 0
(the handle of the default pfifo child Qdiscs). Since iproute2 does not
print a child Qdisc handle of 0, adjust the test's expected output.

Link: https://lore.kernel.org/netdev/3b83fcf6-a5e8-26fb-8c8a-ec34ec4c3342@mojatatu.com/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-6-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-09 15:59:21 -07:00
Vladimir Oltean
6e0ec800c1 net/sched: taprio: delete misleading comment about preallocating child qdiscs
As mentioned in commit af7b29b1de ("Revert "net/sched: taprio: make
qdisc_leaf() see the per-netdev-queue pfifo child qdiscs"") - unlike
mqprio, taprio doesn't use q->qdiscs[] only as a temporary transport
between Qdisc_ops :: init() and Qdisc_ops :: attach().

Delete the comment, which is just stolen from mqprio, but there, the
usage patterns are a lot different, and this is nothing but confusing.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-5-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-09 15:59:20 -07:00
Vladimir Oltean
98766add2d net/sched: taprio: try again to report q->qdiscs[] to qdisc_leaf()
This is another stab at commit 1461d212ab ("net/sched: taprio: make
qdisc_leaf() see the per-netdev-queue pfifo child qdiscs"), later
reverted in commit af7b29b1de ("Revert "net/sched: taprio: make
qdisc_leaf() see the per-netdev-queue pfifo child qdiscs"").

I believe that the problems that caused the revert were fixed, and thus,
this change is identical to the original patch.

Its purpose is to properly reject attaching a software taprio child
qdisc to a software taprio parent. Because unoffloaded taprio currently
reports itself (the root Qdisc) as the return value from qdisc_leaf(),
then the process of attaching another taprio as child to a Qdisc class
of the root will just result in a Qdisc_ops :: change() call for the
root. Whereas that's not we want. We want Qdisc_ops :: init() to be
called for the taprio child, in order to give the taprio child a chance
to check whether its sch->parent is TC_H_ROOT or not (and reject this
configuration).

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-4-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-09 15:59:20 -07:00
Vladimir Oltean
25b0d4e4e4 net/sched: taprio: keep child Qdisc refcount elevated at 2 in offload mode
Normally, Qdiscs have one reference on them held by their owner and one
held for each TXQ to which they are attached, however this is not the
case with the children of an offloaded taprio. Instead, the taprio qdisc
currently lives in the following fragile equilibrium.

In the software scheduling case, taprio attaches itself (the root Qdisc)
to all TXQs, thus having a refcount of 1 + the number of TX queues. In
this mode, the q->qdiscs[] children are not visible directly to the
Qdisc API. The lifetime of the Qdiscs from this private array lasts
until qdisc_destroy() -> taprio_destroy().

In the fully offloaded case, the root taprio has a refcount of 1, and
all child q->qdiscs[] also have a refcount of 1. The child q->qdiscs[]
are attached to the netdev TXQs directly and thus are visible to the
Qdisc API, however taprio loses a reference to them very early - during
qdisc_graft(parent==NULL) -> taprio_attach(). At that time, taprio frees
the q->qdiscs[] array to not leak memory, but interestingly, it does not
release a reference on these qdiscs because it doesn't effectively own
them - they are created by taprio but owned by the Qdisc core, and will
be freed by qdisc_graft(parent==NULL, new==NULL) -> qdisc_put(old) when
the Qdisc is deleted or when the child Qdisc is replaced with something
else.

My interest is to change this equilibrium such that taprio also owns a
reference on the q->qdiscs[] child Qdiscs for the lifetime of the root
Qdisc, including in full offload mode. I want this because I would like
taprio_leaf(), taprio_dump_class(), taprio_dump_class_stats() to have
insight into q->qdiscs[] for the software scheduling mode - currently
they look at dev_queue->qdisc_sleeping, which is, as mentioned, the same
as the root taprio.

The following set of changes is necessary:
- don't free q->qdiscs[] early in taprio_attach(), free it late in
  taprio_destroy() for consistency with software mode. But:
- currently that's not possible, because taprio doesn't own a reference
  on q->qdiscs[]. So hold that reference - once during the initial
  attach() and once during subsequent graft() calls when the child is
  changed.
- always keep track of the current child in q->qdiscs[], even for full
  offload mode, so that we free in taprio_destroy() what we should, and
  not something stale.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-3-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-09 15:59:20 -07:00
Vladimir Oltean
09e0c3bbde net/sched: taprio: don't access q->qdiscs[] in unoffloaded mode during attach()
This is a simple code transformation with no intended behavior change,
just to make it absolutely clear that q->qdiscs[] is only attached to
the child taprio classes in full offload mode.

Right now we use the q->qdiscs[] variable in taprio_attach() for
software mode too, but that is quite confusing and avoidable. We use
it only to reach the netdev TX queue, but we could as well just use
netdev_get_tx_queue() for that.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-09 15:59:20 -07:00
Jakub Kicinski
35b1b1fd96 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/dsa/port.c
  9945c1fb03 ("net: dsa: fix older DSA drivers using phylink")
  a88dd75384 ("net: dsa: remove legacy_pre_march2020 detection")
https://lore.kernel.org/all/20230731102254.2c9868ca@canb.auug.org.au/

net/xdp/xsk.c
  3c5b4d69c3 ("net: annotate data-races around sk->sk_mark")
  b7f72a30e9 ("xsk: introduce wrappers and helpers for supporting multi-buffer in Tx path")
https://lore.kernel.org/all/20230731102631.39988412@canb.auug.org.au/

drivers/net/ethernet/broadcom/bnxt/bnxt.c
  37b61cda9c ("bnxt: don't handle XDP in netpoll")
  2b56b3d992 ("eth: bnxt: handle invalid Tx completions more gracefully")
https://lore.kernel.org/all/20230801101708.1dc7faac@canb.auug.org.au/

Adjacent changes:

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c
  62da08331f ("net/mlx5e: Set proper IPsec source port in L4 selector")
  fbd517549c ("net/mlx5e: Add function to get IPsec offload namespace")

drivers/net/ethernet/sfc/selftest.c
  55c1528f9b ("sfc: fix field-spanning memcpy in selftest")
  ae9d445cd4 ("sfc: Miscellaneous comment removals")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-03 14:34:37 -07:00
Ratheesh Kannoth
4c13eda757 tc: flower: support for SPI
tc flower rules support to classify ESP/AH
packets matching SPI field.

Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-02 10:09:31 +01:00
Pedro Tammela
e20e75017c net/sched: sch_qfq: warn about class in use while deleting
Add extack to warn that delete was rejected because
the class is still in use

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-01 10:47:25 +02:00
Pedro Tammela
7118f56e04 net/sched: sch_htb: warn about class in use while deleting
Add extack to warn that delete was rejected because
the class is still in use

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-01 10:47:24 +02:00
Pedro Tammela
8e4553ef3e net/sched: sch_hfsc: warn about class in use while deleting
Add extack to warn that delete was rejected because
the class is still in use

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-01 10:47:24 +02:00
Pedro Tammela
daf8d9181b net/sched: sch_drr: warn about class in use while deleting
Add extack to warn that delete was rejected because
the class is still in use

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-01 10:47:24 +02:00
Pedro Tammela
8798481b66 net/sched: wrap open coded Qdics class filter counter
The 'filter_cnt' counter is used to control a Qdisc class lifetime.
Each filter referecing this class by its id will eventually
increment/decrement this counter in their respective
'add/update/delete' routines.
As these operations are always serialized under rtnl lock, we don't
need an atomic type like 'refcount_t'.

It also means that we lose the overflow/underflow checks already
present in refcount_t, which are valuable to hunt down bugs
where the unsigned counter wraps around as it aids automated tools
like syzkaller to scream in such situations.

Wrap the open coded increment/decrement into helper functions and
add overflow checks to the operations.

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-01 10:47:24 +02:00
valis
b80b829e9e net/sched: cls_route: No longer copy tcf_result on update to avoid use-after-free
When route4_change() is called on an existing filter, the whole
tcf_result struct is always copied into the new instance of the filter.

This causes a problem when updating a filter bound to a class,
as tcf_unbind_filter() is always called on the old instance in the
success path, decreasing filter_cnt of the still referenced class
and allowing it to be deleted, leading to a use-after-free.

Fix this by no longer copying the tcf_result struct from the old filter.

Fixes: 1109c00547 ("net: sched: RCU cls_route")
Reported-by: valis <sec@valis.email>
Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: M A Ramdhan <ramdhan@starlabs.sg>
Link: https://lore.kernel.org/r/20230729123202.72406-4-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-31 20:10:37 -07:00
valis
76e42ae831 net/sched: cls_fw: No longer copy tcf_result on update to avoid use-after-free
When fw_change() is called on an existing filter, the whole
tcf_result struct is always copied into the new instance of the filter.

This causes a problem when updating a filter bound to a class,
as tcf_unbind_filter() is always called on the old instance in the
success path, decreasing filter_cnt of the still referenced class
and allowing it to be deleted, leading to a use-after-free.

Fix this by no longer copying the tcf_result struct from the old filter.

Fixes: e35a8ee599 ("net: sched: fw use RCU")
Reported-by: valis <sec@valis.email>
Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: M A Ramdhan <ramdhan@starlabs.sg>
Link: https://lore.kernel.org/r/20230729123202.72406-3-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-31 20:10:36 -07:00
valis
3044b16e7c net/sched: cls_u32: No longer copy tcf_result on update to avoid use-after-free
When u32_change() is called on an existing filter, the whole
tcf_result struct is always copied into the new instance of the filter.

This causes a problem when updating a filter bound to a class,
as tcf_unbind_filter() is always called on the old instance in the
success path, decreasing filter_cnt of the still referenced class
and allowing it to be deleted, leading to a use-after-free.

Fix this by no longer copying the tcf_result struct from the old filter.

Fixes: de5df63228 ("net: sched: cls_u32 changes to knode must appear atomic to readers")
Reported-by: valis <sec@valis.email>
Reported-by: M A Ramdhan <ramdhan@starlabs.sg>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: M A Ramdhan <ramdhan@starlabs.sg>
Link: https://lore.kernel.org/r/20230729123202.72406-2-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-31 20:10:36 -07:00
Kuniyuki Iwashima
e739718444 net/sched: taprio: Limit TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME to INT_MAX.
syzkaller found zero division error [0] in div_s64_rem() called from
get_cycle_time_elapsed(), where sched->cycle_time is the divisor.

We have tests in parse_taprio_schedule() so that cycle_time will never
be 0, and actually cycle_time is not 0 in get_cycle_time_elapsed().

The problem is that the types of divisor are different; cycle_time is
s64, but the argument of div_s64_rem() is s32.

syzkaller fed this input and 0x100000000 is cast to s32 to be 0.

  @TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME={0xc, 0x8, 0x100000000}

We use s64 for cycle_time to cast it to ktime_t, so let's keep it and
set max for cycle_time.

While at it, we prevent overflow in setup_txtime() and add another
test in parse_taprio_schedule() to check if cycle_time overflows.

Also, we add a new tdc test case for this issue.

[0]:
divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 PID: 103 Comm: kworker/1:3 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:div_s64_rem include/linux/math64.h:42 [inline]
RIP: 0010:get_cycle_time_elapsed net/sched/sch_taprio.c:223 [inline]
RIP: 0010:find_entry_to_transmit+0x252/0x7e0 net/sched/sch_taprio.c:344
Code: 3c 02 00 0f 85 5e 05 00 00 48 8b 4c 24 08 4d 8b bd 40 01 00 00 48 8b 7c 24 48 48 89 c8 4c 29 f8 48 63 f7 48 99 48 89 74 24 70 <48> f7 fe 48 29 d1 48 8d 04 0f 49 89 cc 48 89 44 24 20 49 8d 85 10
RSP: 0018:ffffc90000acf260 EFLAGS: 00010206
RAX: 177450e0347560cf RBX: 0000000000000000 RCX: 177450e0347560cf
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000100000000
RBP: 0000000000000056 R08: 0000000000000000 R09: ffffed10020a0934
R10: ffff8880105049a7 R11: ffff88806cf3a520 R12: ffff888010504800
R13: ffff88800c00d800 R14: ffff8880105049a0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0edf84f0e8 CR3: 000000000d73c002 CR4: 0000000000770ee0
PKRU: 55555554
Call Trace:
 <TASK>
 get_packet_txtime net/sched/sch_taprio.c:508 [inline]
 taprio_enqueue_one+0x900/0xff0 net/sched/sch_taprio.c:577
 taprio_enqueue+0x378/0xae0 net/sched/sch_taprio.c:658
 dev_qdisc_enqueue+0x46/0x170 net/core/dev.c:3732
 __dev_xmit_skb net/core/dev.c:3821 [inline]
 __dev_queue_xmit+0x1b2f/0x3000 net/core/dev.c:4169
 dev_queue_xmit include/linux/netdevice.h:3088 [inline]
 neigh_resolve_output net/core/neighbour.c:1552 [inline]
 neigh_resolve_output+0x4a7/0x780 net/core/neighbour.c:1532
 neigh_output include/net/neighbour.h:544 [inline]
 ip6_finish_output2+0x924/0x17d0 net/ipv6/ip6_output.c:135
 __ip6_finish_output+0x620/0xaa0 net/ipv6/ip6_output.c:196
 ip6_finish_output net/ipv6/ip6_output.c:207 [inline]
 NF_HOOK_COND include/linux/netfilter.h:292 [inline]
 ip6_output+0x206/0x410 net/ipv6/ip6_output.c:228
 dst_output include/net/dst.h:458 [inline]
 NF_HOOK.constprop.0+0xea/0x260 include/linux/netfilter.h:303
 ndisc_send_skb+0x872/0xe80 net/ipv6/ndisc.c:508
 ndisc_send_ns+0xb5/0x130 net/ipv6/ndisc.c:666
 addrconf_dad_work+0xc14/0x13f0 net/ipv6/addrconf.c:4175
 process_one_work+0x92c/0x13a0 kernel/workqueue.c:2597
 worker_thread+0x60f/0x1240 kernel/workqueue.c:2748
 kthread+0x2fe/0x3f0 kernel/kthread.c:389
 ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308
 </TASK>
Modules linked in:

Fixes: 4cfd5779bd ("taprio: Add support for txtime-assist mode")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Co-developed-by: Eric Dumazet <edumazet@google.com>
Co-developed-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-31 09:12:27 +01:00
Eric Dumazet
285975dd67 net: annotate data-races around sk->sk_{rcv|snd}timeo
sk_getsockopt() runs without locks, we must add annotations
to sk->sk_rcvtimeo and sk->sk_sndtimeo.

In the future we might allow fetching these fields before
we lock the socket in TCP fast path.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-29 18:13:41 +01:00
Jamal Hadi Salim
e68409db99 net: sched: cls_u32: Fix match key mis-addressing
A match entry is uniquely identified with an "address" or "path" in the
form of: hashtable ID(12b):bucketid(8b):nodeid(12b).

When creating table match entries all of hash table id, bucket id and
node (match entry id) are needed to be either specified by the user or
reasonable in-kernel defaults are used. The in-kernel default for a table id is
0x800(omnipresent root table); for bucketid it is 0x0. Prior to this fix there
was none for a nodeid i.e. the code assumed that the user passed the correct
nodeid and if the user passes a nodeid of 0 (as Mingi Cho did) then that is what
was used. But nodeid of 0 is reserved for identifying the table. This is not
a problem until we dump. The dump code notices that the nodeid is zero and
assumes it is referencing a table and therefore references table struct
tc_u_hnode instead of what was created i.e match entry struct tc_u_knode.

Ming does an equivalent of:
tc filter add dev dummy0 parent 10: prio 1 handle 0x1000 \
protocol ip u32 match ip src 10.0.0.1/32 classid 10:1 action ok

Essentially specifying a table id 0, bucketid 1 and nodeid of zero
Tableid 0 is remapped to the default of 0x800.
Bucketid 1 is ignored and defaults to 0x00.
Nodeid was assumed to be what Ming passed - 0x000

dumping before fix shows:
~$ tc filter ls dev dummy0 parent 10:
filter protocol ip pref 1 u32 chain 0
filter protocol ip pref 1 u32 chain 0 fh 800: ht divisor 1
filter protocol ip pref 1 u32 chain 0 fh 800: ht divisor -30591

Note that the last line reports a table instead of a match entry
(you can tell this because it says "ht divisor...").
As a result of reporting the wrong data type (misinterpretting of struct
tc_u_knode as being struct tc_u_hnode) the divisor is reported with value
of -30591. Ming identified this as part of the heap address
(physmap_base is 0xffff8880 (-30591 - 1)).

The fix is to ensure that when table entry matches are added and no
nodeid is specified (i.e nodeid == 0) then we get the next available
nodeid from the table's pool.

After the fix, this is what the dump shows:
$ tc filter ls dev dummy0 parent 10:
filter protocol ip pref 1 u32 chain 0
filter protocol ip pref 1 u32 chain 0 fh 800: ht divisor 1
filter protocol ip pref 1 u32 chain 0 fh 800::800 order 2048 key ht 800 bkt 0 flowid 10:1 not_in_hw
  match 0a000001/ffffffff at 12
	action order 1: gact action pass
	 random type none pass val 0
	 index 1 ref 1 bind 1

Reported-by: Mingi Cho <mgcho.minic@gmail.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230726135151.416917-1-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-28 18:05:04 -07:00
Eric Dumazet
4d50e50045 net: flower: fix stack-out-of-bounds in fl_set_key_cfm()
Typical misuse of

	nla_parse_nested(array, XXX_MAX, ...);

array must be declared as

	struct nlattr *array[XXX_MAX + 1];

v2: Based on feedbacks from Ido Schimmel and Zahari Doychev,
I also changed TCA_FLOWER_KEY_CFM_OPT_MAX and cfm_opt_policy
definitions.

syzbot reported:

BUG: KASAN: stack-out-of-bounds in __nla_validate_parse+0x136/0x2bd0 lib/nlattr.c:588
Write of size 32 at addr ffffc90003a0ee20 by task syz-executor296/5014

CPU: 0 PID: 5014 Comm: syz-executor296 Not tainted 6.5.0-rc2-syzkaller-00307-gd192f5382581 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0x163/0x540 mm/kasan/report.c:475
kasan_report+0x175/0x1b0 mm/kasan/report.c:588
kasan_check_range+0x27e/0x290 mm/kasan/generic.c:187
__asan_memset+0x23/0x40 mm/kasan/shadow.c:84
__nla_validate_parse+0x136/0x2bd0 lib/nlattr.c:588
__nla_parse+0x40/0x50 lib/nlattr.c:700
nla_parse_nested include/net/netlink.h:1262 [inline]
fl_set_key_cfm+0x1e3/0x440 net/sched/cls_flower.c:1718
fl_set_key+0x2168/0x6620 net/sched/cls_flower.c:1884
fl_tmplt_create+0x1fe/0x510 net/sched/cls_flower.c:2666
tc_chain_tmplt_add net/sched/cls_api.c:2959 [inline]
tc_ctl_chain+0x131d/0x1ac0 net/sched/cls_api.c:3068
rtnetlink_rcv_msg+0x82b/0xf50 net/core/rtnetlink.c:6424
netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2549
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x7c3/0x990 net/netlink/af_netlink.c:1365
netlink_sendmsg+0xa2a/0xd60 net/netlink/af_netlink.c:1914
sock_sendmsg_nosec net/socket.c:725 [inline]
sock_sendmsg net/socket.c:748 [inline]
____sys_sendmsg+0x592/0x890 net/socket.c:2494
___sys_sendmsg net/socket.c:2548 [inline]
__sys_sendmsg+0x2b0/0x3a0 net/socket.c:2577
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f54c6150759
Code: 48 83 c4 28 c3 e8 d7 19 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe06c30578 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f54c619902d RCX: 00007f54c6150759
RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000003
RBP: 00007ffe06c30590 R08: 0000000000000000 R09: 00007ffe06c305f0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f54c61c35f0
R13: 00007ffe06c30778 R14: 0000000000000001 R15: 0000000000000001
</TASK>

The buggy address belongs to stack of task syz-executor296/5014
and is located at offset 32 in frame:
fl_set_key_cfm+0x0/0x440 net/sched/cls_flower.c:374

This frame has 1 object:
[32, 56) 'nla_cfm_opt'

The buggy address belongs to the virtual mapping at
[ffffc90003a08000, ffffc90003a11000) created by:
copy_process+0x5c8/0x4290 kernel/fork.c:2330

Fixes: 7cfffd5fed ("net: flower: add support for matching cfm fields")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Zahari Doychev <zdoychev@maxlinear.com>
Link: https://lore.kernel.org/r/20230726145815.943910-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-27 20:01:29 -07:00
Jakub Kicinski
014acf2668 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-27 15:22:46 -07:00
Lin Ma
6c58c8816a net/sched: mqprio: Add length check for TCA_MQPRIO_{MAX/MIN}_RATE64
The nla_for_each_nested parsing in function mqprio_parse_nlattr() does
not check the length of the nested attribute. This can lead to an
out-of-attribute read and allow a malformed nlattr (e.g., length 0) to
be viewed as 8 byte integer and passed to priv->max_rate/min_rate.

This patch adds the check based on nla_len() when check the nla_type(),
which ensures that the length of these two attribute must equals
sizeof(u64).

Fixes: 4e8b86c062 ("mqprio: Introduce new hardware offload mode and shaper in mqprio")
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Link: https://lore.kernel.org/r/20230725024227.426561-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-26 22:08:14 -07:00
Daniel Borkmann
dc644b540a tcx: Fix splat in ingress_destroy upon tcx_entry_free
On qdisc destruction, the ingress_destroy() needs to update the correct
entry, that is, tcx_entry_update must NULL the dev->tcx_ingress pointer.
Therefore, fix the typo.

Fixes: e420bed025 ("bpf: Add fd-based tcx multi-prog infra with link support")
Reported-by: syzbot+bdcf141f362ef83335cf@syzkaller.appspotmail.com
Reported-by: syzbot+b202b7208664142954fa@syzkaller.appspotmail.com
Reported-by: syzbot+14736e249bce46091c18@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+bdcf141f362ef83335cf@syzkaller.appspotmail.com
Tested-by: syzbot+b202b7208664142954fa@syzkaller.appspotmail.com
Tested-by: syzbot+14736e249bce46091c18@syzkaller.appspotmail.com
Tested-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/20230721233330.5678-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-24 11:42:35 -07:00
Naveen Mamindlapalli
9fe63d5f1d sch_htb: Allow HTB quantum parameter in offload mode
The current implementation of HTB offload returns the EINVAL error for
quantum parameter. This patch removes the error returning checks for
'quantum' parameter and populates its value to tc_htb_qopt_offload
structure such that driver can use the same.

Add quantum parameter check in mlx5 driver, as mlx5 devices are not capable
of supporting the quantum parameter when htb offload is used. Report error
if quantum parameter is set to a non-default value.

Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com>
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-21 09:55:53 +01:00
Jakub Kicinski
59be3baa8d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20 15:52:55 -07:00
Xin Long
76622ced50 net: sched: set IPS_CONFIRMED in tmpl status only when commit is set in act_ct
With the following flows, the packets will be dropped if OVS TC offload is
enabled.

  'ip,ct_state=-trk,in_port=1 actions=ct(zone=1)'
  'ip,ct_state=+trk+new+rel,in_port=1 actions=ct(commit,zone=1)'
  'ip,ct_state=+trk+new+rel,in_port=1 actions=ct(commit,zone=2),normal'

In the 1st flow, it finds the exp from the hashtable and removes it then
creates the ct with this exp in act_ct. However, in the 2nd flow it goes
to the OVS upcall at the 1st time. When the skb comes back from userspace,
it has to create the ct again without exp(the exp was removed last time).
With no 'rel' set in the ct, the 3rd flow can never get matched.

In OVS conntrack, it works around it by adding its own exp lookup function
ovs_ct_expect_find() where it doesn't remove the exp. Instead of creating
a real ct, it only updates its keys with the exp and its master info. So
when the skb comes back, the exp is still in the hashtable.

However, we can't do this trick in act_ct, as tc flower match is using a
real ct, and passing the exp and its master info to flower parsing via
tc_skb_cb is also not possible (tc_skb_cb size is not big enough).

The simple and clear fix is to not remove the exp at the 1st flow, namely,
not set IPS_CONFIRMED in tmpl when commit is not set in act_ct.

Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-07-20 10:06:36 +02:00
Daniel Borkmann
e420bed025 bpf: Add fd-based tcx multi-prog infra with link support
This work refactors and adds a lightweight extension ("tcx") to the tc BPF
ingress and egress data path side for allowing BPF program management based
on fds via bpf() syscall through the newly added generic multi-prog API.
The main goal behind this work which we also presented at LPC [0] last year
and a recent update at LSF/MM/BPF this year [3] is to support long-awaited
BPF link functionality for tc BPF programs, which allows for a model of safe
ownership and program detachment.

Given the rise in tc BPF users in cloud native environments, this becomes
necessary to avoid hard to debug incidents either through stale leftover
programs or 3rd party applications accidentally stepping on each others toes.
As a recap, a BPF link represents the attachment of a BPF program to a BPF
hook point. The BPF link holds a single reference to keep BPF program alive.
Moreover, hook points do not reference a BPF link, only the application's
fd or pinning does. A BPF link holds meta-data specific to attachment and
implements operations for link creation, (atomic) BPF program update,
detachment and introspection. The motivation for BPF links for tc BPF programs
is multi-fold, for example:

  - From Meta: "It's especially important for applications that are deployed
    fleet-wide and that don't "control" hosts they are deployed to. If such
    application crashes and no one notices and does anything about that, BPF
    program will keep running draining resources or even just, say, dropping
    packets. We at FB had outages due to such permanent BPF attachment
    semantics. With fd-based BPF link we are getting a framework, which allows
    safe, auto-detachable behavior by default, unless application explicitly
    opts in by pinning the BPF link." [1]

  - From Cilium-side the tc BPF programs we attach to host-facing veth devices
    and phys devices build the core datapath for Kubernetes Pods, and they
    implement forwarding, load-balancing, policy, EDT-management, etc, within
    BPF. Currently there is no concept of 'safe' ownership, e.g. we've recently
    experienced hard-to-debug issues in a user's staging environment where
    another Kubernetes application using tc BPF attached to the same prio/handle
    of cls_bpf, accidentally wiping all Cilium-based BPF programs from underneath
    it. The goal is to establish a clear/safe ownership model via links which
    cannot accidentally be overridden. [0,2]

BPF links for tc can co-exist with non-link attachments, and the semantics are
in line also with XDP links: BPF links cannot replace other BPF links, BPF
links cannot replace non-BPF links, non-BPF links cannot replace BPF links and
lastly only non-BPF links can replace non-BPF links. In case of Cilium, this
would solve mentioned issue of safe ownership model as 3rd party applications
would not be able to accidentally wipe Cilium programs, even if they are not
BPF link aware.

Earlier attempts [4] have tried to integrate BPF links into core tc machinery
to solve cls_bpf, which has been intrusive to the generic tc kernel API with
extensions only specific to cls_bpf and suboptimal/complex since cls_bpf could
be wiped from the qdisc also. Locking a tc BPF program in place this way, is
getting into layering hacks given the two object models are vastly different.

We instead implemented the tcx (tc 'express') layer which is an fd-based tc BPF
attach API, so that the BPF link implementation blends in naturally similar to
other link types which are fd-based and without the need for changing core tc
internal APIs. BPF programs for tc can then be successively migrated from classic
cls_bpf to the new tc BPF link without needing to change the program's source
code, just the BPF loader mechanics for attaching is sufficient.

For the current tc framework, there is no change in behavior with this change
and neither does this change touch on tc core kernel APIs. The gist of this
patch is that the ingress and egress hook have a lightweight, qdisc-less
extension for BPF to attach its tc BPF programs, in other words, a minimal
entry point for tc BPF. The name tcx has been suggested from discussion of
earlier revisions of this work as a good fit, and to more easily differ between
the classic cls_bpf attachment and the fd-based one.

For the ingress and egress tcx points, the device holds a cache-friendly array
with program pointers which is separated from control plane (slow-path) data.
Earlier versions of this work used priority to determine ordering and expression
of dependencies similar as with classic tc, but it was challenged that for
something more future-proof a better user experience is required. Hence this
resulted in the design and development of the generic attach/detach/query API
for multi-progs. See prior patch with its discussion on the API design. tcx is
the first user and later we plan to integrate also others, for example, one
candidate is multi-prog support for XDP which would benefit and have the same
'look and feel' from API perspective.

The goal with tcx is to have maximum compatibility to existing tc BPF programs,
so they don't need to be rewritten specifically. Compatibility to call into
classic tcf_classify() is also provided in order to allow successive migration
or both to cleanly co-exist where needed given its all one logical tc layer and
the tcx plus classic tc cls/act build one logical overall processing pipeline.

tcx supports the simplified return codes TCX_NEXT which is non-terminating (go
to next program) and terminating ones with TCX_PASS, TCX_DROP, TCX_REDIRECT.
The fd-based API is behind a static key, so that when unused the code is also
not entered. The struct tcx_entry's program array is currently static, but
could be made dynamic if necessary at a point in future. The a/b pair swap
design has been chosen so that for detachment there are no allocations which
otherwise could fail.

The work has been tested with tc-testing selftest suite which all passes, as
well as the tc BPF tests from the BPF CI, and also with Cilium's L4LB.

Thanks also to Nikolay Aleksandrov and Martin Lau for in-depth early reviews
of this work.

  [0] https://lpc.events/event/16/contributions/1353/
  [1] https://lore.kernel.org/bpf/CAEf4BzbokCJN33Nw_kg82sO=xppXnKWEncGTWCTB9vGCmLB6pw@mail.gmail.com
  [2] https://colocatedeventseu2023.sched.com/event/1Jo6O/tales-from-an-ebpf-programs-murder-mystery-hemanth-malla-guillaume-fournier-datadog
  [3] http://vger.kernel.org/bpfconf2023_material/tcx_meta_netdev_borkmann.pdf
  [4] https://lore.kernel.org/bpf/20210604063116.234316-1-memxor@gmail.com

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230719140858.13224-3-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-19 10:07:27 -07:00
Victor Nogueira
ac177a3300 net: sched: cls_flower: Undo tcf_bind_filter in case of an error
If TCA_FLOWER_CLASSID is specified in the netlink message, the code will
call tcf_bind_filter. However, if any error occurs after that, the code
should undo this by calling tcf_unbind_filter.

Fixes: 77b9900ef5 ("tc: introduce Flower classifier")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-17 07:33:39 +01:00
Victor Nogueira
26a2219492 net: sched: cls_bpf: Undo tcf_bind_filter in case of an error
If cls_bpf_offload errors out, we must also undo tcf_bind_filter that
was done before the error.

Fix that by calling tcf_unbind_filter in errout_parms.

Fixes: eadb41489f ("net: cls_bpf: add support for marking filters as hardware-only")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-17 07:33:39 +01:00
Victor Nogueira
e8d3d78c19 net: sched: cls_u32: Undo refcount decrement in case update failed
In the case of an update, when TCA_U32_LINK is set, u32_set_parms will
decrement the refcount of the ht_down (struct tc_u_hnode) pointer
present in the older u32 filter which we are replacing. However, if
u32_replace_hw_knode errors out, the update command fails and that
ht_down pointer continues decremented. To fix that, when
u32_replace_hw_knode fails, check if ht_down's refcount was decremented
and undo the decrement.

Fixes: d34e3e1813 ("net: cls_u32: Add support for skip-sw flag to tc u32 classifier.")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-17 07:33:38 +01:00
Victor Nogueira
9cb36faede net: sched: cls_u32: Undo tcf_bind_filter if u32_replace_hw_knode
When u32_replace_hw_knode fails, we need to undo the tcf_bind_filter
operation done at u32_set_parms.

Fixes: d34e3e1813 ("net: cls_u32: Add support for skip-sw flag to tc u32 classifier.")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-17 07:33:38 +01:00