linux-stable/net/sched
Eric Dumazet 2174a08db8 sch_netem: acquire qdisc lock in netem_change()
syzbot managed to trigger a divide error [1] in netem.

It could happen if q->rate changes while netem_enqueue()
is running, since q->rate is read twice.

It turns out netem_change() always lacked proper synchronization.

[1]
divide error: 0000 [#1] SMP KASAN
CPU: 1 PID: 7867 Comm: syz-executor.1 Not tainted 6.1.30-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:div64_u64 include/linux/math64.h:69 [inline]
RIP: 0010:packet_time_ns net/sched/sch_netem.c:357 [inline]
RIP: 0010:netem_enqueue+0x2067/0x36d0 net/sched/sch_netem.c:576
Code: 89 e2 48 69 da 00 ca 9a 3b 42 80 3c 28 00 4c 8b a4 24 88 00 00 00 74 0d 4c 89 e7 e8 c3 4f 3b fd 48 8b 4c 24 18 48 89 d8 31 d2 <49> f7 34 24 49 01 c7 4c 8b 64 24 48 4d 01 f7 4c 89 e3 48 c1 eb 03
RSP: 0018:ffffc9000dccea60 EFLAGS: 00010246
RAX: 000001a442624200 RBX: 000001a442624200 RCX: ffff888108a4f000
RDX: 0000000000000000 RSI: 000000000000070d RDI: 000000000000070d
RBP: ffffc9000dcceb90 R08: ffffffff849c5e26 R09: fffffbfff10e1297
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888108a4f358
R13: dffffc0000000000 R14: 0000001a8cd9a7ec R15: 0000000000000000
FS: 00007fa73fe18700(0000) GS:ffff8881f6b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa73fdf7718 CR3: 000000011d36e000 CR4: 0000000000350ee0
Call Trace:
<TASK>
[<ffffffff84714385>] __dev_xmit_skb net/core/dev.c:3931 [inline]
[<ffffffff84714385>] __dev_queue_xmit+0xcf5/0x3370 net/core/dev.c:4290
[<ffffffff84d22df2>] dev_queue_xmit include/linux/netdevice.h:3030 [inline]
[<ffffffff84d22df2>] neigh_hh_output include/net/neighbour.h:531 [inline]
[<ffffffff84d22df2>] neigh_output include/net/neighbour.h:545 [inline]
[<ffffffff84d22df2>] ip_finish_output2+0xb92/0x10d0 net/ipv4/ip_output.c:235
[<ffffffff84d21e63>] __ip_finish_output+0xc3/0x2b0
[<ffffffff84d10a81>] ip_finish_output+0x31/0x2a0 net/ipv4/ip_output.c:323
[<ffffffff84d10f14>] NF_HOOK_COND include/linux/netfilter.h:298 [inline]
[<ffffffff84d10f14>] ip_output+0x224/0x2a0 net/ipv4/ip_output.c:437
[<ffffffff84d123b5>] dst_output include/net/dst.h:444 [inline]
[<ffffffff84d123b5>] ip_local_out net/ipv4/ip_output.c:127 [inline]
[<ffffffff84d123b5>] __ip_queue_xmit+0x1425/0x2000 net/ipv4/ip_output.c:542
[<ffffffff84d12fdc>] ip_queue_xmit+0x4c/0x70 net/ipv4/ip_output.c:556

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230620184425.1179809-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-06-22 10:58:52 +02:00
..
act_api.c net/sched: act_api: use the correct TCA_ACT attributes in dump 2023-03-23 08:39:08 +00:00
act_bpf.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_connmark.c net/sched: act_connmark: handle errno on tcf_idr_check_alloc 2023-03-01 08:19:09 +00:00
act_csum.c net: skbuff: hide csum_not_inet when CONFIG_IP_SCTP not set 2023-04-19 13:04:30 +01:00
act_ct.c net/sched: act_ct: Fix promotion of offloaded unreplied tuple 2023-06-14 09:56:50 +02:00
act_ctinfo.c net/sched: act_ctinfo: use percpu stats 2023-02-13 20:09:01 -08:00
act_gact.c Networking changes for 6.2. 2022-12-13 15:47:48 -08:00
act_gate.c net/sched: act_gate: use percpu stats 2023-02-16 10:39:28 +01:00
act_ife.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_ipt.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_meta_mark.c
act_meta_skbprio.c
act_meta_skbtcindex.c
act_mirred.c net/sched: act_mirred: Add carrier check 2023-05-01 07:26:10 +01:00
act_mpls.c net/sched: remove two skb_mac_header() uses 2023-03-22 22:43:23 -07:00
act_nat.c net/sched: act_nat: transition to percpu stats and rcu 2023-02-16 10:39:28 +01:00
act_pedit.c net/sched: act_pedit: Parse L3 Header for L4 offset 2023-06-09 10:34:27 +01:00
act_police.c net: sched: act_police: fix sparse errors in tcf_police_dump() 2023-06-07 12:28:04 +01:00
act_sample.c net/sched: act_sample: fix action bind logic 2023-02-26 18:27:45 +00:00
act_simple.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_skbedit.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_skbmod.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_tunnel_key.c net/sched: act_tunnel_key: add support for "don't fragment" 2023-03-30 23:24:24 -07:00
act_vlan.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
cls_api.c net/sched: cls_api: Fix lockup on flushing explicitly created chain 2023-06-14 23:03:16 -07:00
cls_basic.c net/sched: avoid indirect classify functions on retpoline kernels 2022-12-09 09:18:07 +00:00
cls_bpf.c net/sched: avoid indirect classify functions on retpoline kernels 2022-12-09 09:18:07 +00:00
cls_cgroup.c net/sched: avoid indirect classify functions on retpoline kernels 2022-12-09 09:18:07 +00:00
cls_flow.c treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
cls_flower.c net/sched: flower: fix possible OOB write in fl_set_geneve_opt() 2023-06-01 12:59:04 +02:00
cls_fw.c net/sched: avoid indirect classify functions on retpoline kernels 2022-12-09 09:18:07 +00:00
cls_matchall.c net/sched: support per action hw stats 2023-02-14 11:00:01 +01:00
cls_route.c net/sched: avoid indirect classify functions on retpoline kernels 2022-12-09 09:18:07 +00:00
cls_u32.c net/sched: cls_u32: Fix reference counter leak leading to overflow 2023-06-09 11:40:17 +01:00
em_canid.c
em_cmp.c
em_ipset.c
em_ipt.c
em_meta.c fix typos in net/sched/* files 2023-03-24 09:05:03 +00:00
em_nbyte.c
em_text.c
em_u32.c
ematch.c net_sched: reject TCF_EM_SIMPLE case for complex ematch module 2022-12-19 09:43:18 +00:00
Kconfig net/sched: Retire rsvp classifier 2023-02-16 09:27:07 +01:00
Makefile net/sched: Retire rsvp classifier 2023-02-16 09:27:07 +01:00
sch_api.c net/sched: qdisc_destroy() old ingress and clsact Qdiscs before grafting 2023-06-14 10:31:39 +02:00
sch_blackhole.c
sch_cake.c sch_cake: do not use skb_mac_header() in cake_overhead() 2023-03-22 22:43:23 -07:00
sch_cbs.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_choke.c treewide: use get_random_u32_below() instead of deprecated function 2022-11-18 02:15:15 +01:00
sch_codel.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_drr.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_etf.c net: sched: etf: remove true check in etf_enable_offload() 2022-09-01 20:08:32 -07:00
sch_ets.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_fifo.c
sch_fq.c net/sched: sch_fq: fix integer overflow of "credit" 2023-04-21 20:24:29 -07:00
sch_fq_codel.c Revert "net: sched: fq_codel: remove redundant resource cleanup in fq_codel_init()" 2022-10-19 13:47:09 +01:00
sch_fq_pie.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_frag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
sch_generic.c net/sched: qdisc_destroy() old ingress and clsact Qdiscs before grafting 2023-06-14 10:31:39 +02:00
sch_gred.c net: sched: gred: prevent races when adding offloads to stats 2023-01-18 20:28:25 -08:00
sch_hfsc.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_hhf.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_htb.c net/sched: sch_htb: use extack on errors messages 2023-04-23 18:47:09 +01:00
sch_ingress.c net/sched: Reserve TC_H_INGRESS (TC_H_CLSACT) for ingress (clsact) Qdiscs 2023-05-30 23:31:05 -07:00
sch_mq.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_mqprio.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_mqprio_lib.c net/sched: mqprio: allow per-TC user input of FP adminStatus 2023-04-13 22:22:10 -07:00
sch_mqprio_lib.h net/sched: mqprio: allow per-TC user input of FP adminStatus 2023-04-13 22:22:10 -07:00
sch_multiq.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_netem.c sch_netem: acquire qdisc lock in netem_change() 2023-06-22 10:58:52 +02:00
sch_pie.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_plug.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_prio.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_qfq.c net/sched: sch_qfq: refactor parsing of netlink parameters 2023-04-23 18:47:09 +01:00
sch_red.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_sfb.c Networking fixes for 6.1-rc2, including fixes from netfilter 2022-10-20 17:24:59 -07:00
sch_sfq.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_skbprio.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_taprio.c net/sched: taprio: fix slab-out-of-bounds Read in taprio_dequeue_from_txq 2023-06-09 10:48:14 +01:00
sch_tbf.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_teql.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00