linux-stable/net/sched
Eric Dumazet d313eb8b77 net/sched: act_skbmod: prevent kernel-infoleak
syzbot found that tcf_skbmod_dump() was copying four bytes
from kernel stack to user space [1].

The issue here is that 'struct tc_skbmod' has a four bytes hole.

We need to clear the structure before filling fields.

[1]
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 BUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline]
 BUG: KMSAN: kernel-infoleak in iterate_ubuf include/linux/iov_iter.h:29 [inline]
 BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
 BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:271 [inline]
 BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185
  instrument_copy_to_user include/linux/instrumented.h:114 [inline]
  copy_to_user_iter lib/iov_iter.c:24 [inline]
  iterate_ubuf include/linux/iov_iter.h:29 [inline]
  iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
  iterate_and_advance include/linux/iov_iter.h:271 [inline]
  _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185
  copy_to_iter include/linux/uio.h:196 [inline]
  simple_copy_to_iter net/core/datagram.c:532 [inline]
  __skb_datagram_iter+0x185/0x1000 net/core/datagram.c:420
  skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:546
  skb_copy_datagram_msg include/linux/skbuff.h:4050 [inline]
  netlink_recvmsg+0x432/0x1610 net/netlink/af_netlink.c:1962
  sock_recvmsg_nosec net/socket.c:1046 [inline]
  sock_recvmsg+0x2c4/0x340 net/socket.c:1068
  __sys_recvfrom+0x35a/0x5f0 net/socket.c:2242
  __do_sys_recvfrom net/socket.c:2260 [inline]
  __se_sys_recvfrom net/socket.c:2256 [inline]
  __x64_sys_recvfrom+0x126/0x1d0 net/socket.c:2256
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was stored to memory at:
  pskb_expand_head+0x30f/0x19d0 net/core/skbuff.c:2253
  netlink_trim+0x2c2/0x330 net/netlink/af_netlink.c:1317
  netlink_unicast+0x9f/0x1260 net/netlink/af_netlink.c:1351
  nlmsg_unicast include/net/netlink.h:1144 [inline]
  nlmsg_notify+0x21d/0x2f0 net/netlink/af_netlink.c:2610
  rtnetlink_send+0x73/0x90 net/core/rtnetlink.c:741
  rtnetlink_maybe_send include/linux/rtnetlink.h:17 [inline]
  tcf_add_notify net/sched/act_api.c:2048 [inline]
  tcf_action_add net/sched/act_api.c:2071 [inline]
  tc_ctl_action+0x146e/0x19d0 net/sched/act_api.c:2119
  rtnetlink_rcv_msg+0x1737/0x1900 net/core/rtnetlink.c:6595
  netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2559
  rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6613
  netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
  netlink_unicast+0xf4c/0x1260 net/netlink/af_netlink.c:1361
  netlink_sendmsg+0x10df/0x11f0 net/netlink/af_netlink.c:1905
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:745
  ____sys_sendmsg+0x877/0xb60 net/socket.c:2584
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
  __sys_sendmsg net/socket.c:2667 [inline]
  __do_sys_sendmsg net/socket.c:2676 [inline]
  __se_sys_sendmsg net/socket.c:2674 [inline]
  __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2674
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was stored to memory at:
  __nla_put lib/nlattr.c:1041 [inline]
  nla_put+0x1c6/0x230 lib/nlattr.c:1099
  tcf_skbmod_dump+0x23f/0xc20 net/sched/act_skbmod.c:256
  tcf_action_dump_old net/sched/act_api.c:1191 [inline]
  tcf_action_dump_1+0x85e/0x970 net/sched/act_api.c:1227
  tcf_action_dump+0x1fd/0x460 net/sched/act_api.c:1251
  tca_get_fill+0x519/0x7a0 net/sched/act_api.c:1628
  tcf_add_notify_msg net/sched/act_api.c:2023 [inline]
  tcf_add_notify net/sched/act_api.c:2042 [inline]
  tcf_action_add net/sched/act_api.c:2071 [inline]
  tc_ctl_action+0x1365/0x19d0 net/sched/act_api.c:2119
  rtnetlink_rcv_msg+0x1737/0x1900 net/core/rtnetlink.c:6595
  netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2559
  rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6613
  netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
  netlink_unicast+0xf4c/0x1260 net/netlink/af_netlink.c:1361
  netlink_sendmsg+0x10df/0x11f0 net/netlink/af_netlink.c:1905
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:745
  ____sys_sendmsg+0x877/0xb60 net/socket.c:2584
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
  __sys_sendmsg net/socket.c:2667 [inline]
  __do_sys_sendmsg net/socket.c:2676 [inline]
  __se_sys_sendmsg net/socket.c:2674 [inline]
  __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2674
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Local variable opt created at:
  tcf_skbmod_dump+0x9d/0xc20 net/sched/act_skbmod.c:244
  tcf_action_dump_old net/sched/act_api.c:1191 [inline]
  tcf_action_dump_1+0x85e/0x970 net/sched/act_api.c:1227

Bytes 188-191 of 248 are uninitialized
Memory access of size 248 starts at ffff888117697680
Data copied to user address 00007ffe56d855f0

Fixes: 86da71b573 ("net_sched: Introduce skbmod action")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240403130908.93421-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-04 09:32:29 -07:00
..
Kconfig net: sched: Remove NET_ACT_IPT from Kconfig 2024-02-13 11:24:35 +01:00
Makefile net/sched: Retire ipt action 2024-01-02 12:41:16 +00:00
act_api.c net/sched: Load modules via their alias 2024-02-02 10:57:55 -08:00
act_bpf.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_connmark.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_csum.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_ct.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_ctinfo.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_gact.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_gate.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_ife.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_meta_mark.c
act_meta_skbprio.c
act_meta_skbtcindex.c
act_mirred.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-02-22 15:29:26 -08:00
act_mpls.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_nat.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_pedit.c net: sched: Annotate struct tc_pedit with __counted_by 2024-02-19 10:58:24 +00:00
act_police.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_sample.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_simple.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_skbedit.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_skbmod.c net/sched: act_skbmod: prevent kernel-infoleak 2024-04-04 09:32:29 -07:00
act_tunnel_key.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_vlan.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_api.c net/sched: Load modules via their alias 2024-02-02 10:57:55 -08:00
cls_basic.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_bpf.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_cgroup.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_flow.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_flower.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-02-22 15:29:26 -08:00
cls_fw.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_matchall.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_route.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_u32.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
em_canid.c net: fill in MODULE_DESCRIPTION()s for net/sched 2024-02-09 14:12:02 -08:00
em_cmp.c net: fill in MODULE_DESCRIPTION()s for net/sched 2024-02-09 14:12:02 -08:00
em_ipset.c
em_ipt.c
em_meta.c net: fill in MODULE_DESCRIPTION()s for net/sched 2024-02-09 14:12:02 -08:00
em_nbyte.c net: fill in MODULE_DESCRIPTION()s for net/sched 2024-02-09 14:12:02 -08:00
em_text.c net: fill in MODULE_DESCRIPTION()s for net/sched 2024-02-09 14:12:02 -08:00
em_u32.c net: fill in MODULE_DESCRIPTION()s for net/sched 2024-02-09 14:12:02 -08:00
ematch.c
sch_api.c net/sched: fix lockdep splat in qdisc_tree_reduce_backlog() 2024-04-03 19:29:42 -07:00
sch_blackhole.c
sch_cake.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_cbs.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_choke.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_codel.c net: sched: codel replace GPLv2/BSD boilerplate 2024-02-13 13:45:19 +01:00
sch_drr.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_etf.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_ets.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_fifo.c net: sched: Fill in missing MODULE_DESCRIPTION for qdiscs 2023-11-01 21:49:09 -07:00
sch_fq.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_fq_codel.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_fq_pie.c net/sched: Add module alias for sch_fq_pie 2024-03-19 15:33:25 +01:00
sch_frag.c net: dst: remove unnecessary input parameter in dst_alloc and dst_init 2023-09-12 11:42:25 +02:00
sch_generic.c net: move dev_tx_weight to net_hotdata 2024-03-07 21:12:42 -08:00
sch_gred.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_hfsc.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_hhf.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_htb.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_ingress.c net/sched: Remove alias of sch_clsact 2024-02-02 10:57:56 -08:00
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 module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_mqprio_lib.c net: sched: Fill in missing MODULE_DESCRIPTION for qdiscs 2023-11-01 21:49:09 -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: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_netem.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_pie.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_plug.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_prio.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_qfq.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_red.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_sfb.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_sfq.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_skbprio.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_taprio.c net/sched: taprio: proper TCA_TAPRIO_TC_ENTRY_INDEX check 2024-03-13 08:26:42 +00:00
sch_tbf.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_teql.c net: sched: Fill in missing MODULE_DESCRIPTION for qdiscs 2023-11-01 21:49:09 -07:00