linux/net/sched
Eric Dumazet 159d2c7d81 sch_netem: fix rcu splat in netem_enqueue()
qdisc_root() use from netem_enqueue() triggers a lockdep warning.

__dev_queue_xmit() uses rcu_read_lock_bh() which is
not equivalent to rcu_read_lock() + local_bh_disable_bh as far
as lockdep is concerned.

WARNING: suspicious RCU usage
5.3.0-rc7+ #0 Not tainted
-----------------------------
include/net/sch_generic.h:492 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by syz-executor427/8855:
 #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline]
 #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2570 net/ipv4/ip_output.c:214
 #1: 00000000b5525c01 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x3650 net/core/dev.c:3804
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline]
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_xmit_skb net/core/dev.c:3502 [inline]
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_queue_xmit+0x14b8/0x3650 net/core/dev.c:3838

stack backtrace:
CPU: 0 PID: 8855 Comm: syz-executor427 Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5357
 qdisc_root include/net/sch_generic.h:492 [inline]
 netem_enqueue+0x1cfb/0x2d80 net/sched/sch_netem.c:479
 __dev_xmit_skb net/core/dev.c:3527 [inline]
 __dev_queue_xmit+0x15d2/0x3650 net/core/dev.c:3838
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0x1726/0x2570 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290
 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_mc_output+0x292/0xf40 net/ipv4/ip_output.c:417
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125
 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1555
 udp_send_skb.isra.0+0x6b2/0x1160 net/ipv4/udp.c:887
 udp_sendmsg+0x1e96/0x2820 net/ipv4/udp.c:1174
 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:657
 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311
 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-27 10:29:11 +02:00
..
act_api.c net_sched: add policy validation for action attributes 2019-09-21 19:33:13 -07:00
act_bpf.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_connmark.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_csum.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_ct.c netfilter: update include directives. 2019-09-13 12:33:06 +02:00
act_ctinfo.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_gact.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_ife.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_ipt.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_meta_mark.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
act_meta_skbprio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
act_meta_skbtcindex.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
act_mirred.c net: sched: use get_dev() action API in flow_action infra 2019-09-16 09:18:03 +02:00
act_mpls.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_nat.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_pedit.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_police.c net_sched: act_police: add 2 new attributes to support police 64bit rate and peakrate 2019-09-06 15:02:16 +02:00
act_sample.c net/sched: act_sample: don't push mac header on ip6gre ingress 2019-09-20 17:01:59 -07:00
act_simple.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_skbedit.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_skbmod.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_tunnel_key.c net_sched: fix a NULL pointer deref in ipt action 2019-08-27 15:05:58 -07:00
act_vlan.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-02 11:20:17 -07:00
cls_api.c net: sched: fix possible crash in tcf_action_destroy() 2019-09-24 16:33:57 +02:00
cls_basic.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cls_bpf.c net: sched: refactor block offloads counter usage 2019-08-26 14:17:43 -07:00
cls_cgroup.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cls_flow.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cls_flower.c net: sched: flower: don't take rtnl lock for cls hw offloads API 2019-08-26 14:17:43 -07:00
cls_fw.c net: sched: remove NET_CLS_IND config option 2019-06-15 14:06:13 -07:00
cls_matchall.c net: sched: cls_matchall: cleanup flow_action before deallocating 2019-08-30 15:12:05 -07:00
cls_route.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cls_rsvp6.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cls_rsvp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cls_rsvp.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cls_tcindex.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
cls_u32.c net: sched: refactor block offloads counter usage 2019-08-26 14:17:43 -07:00
em_canid.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 11 2019-05-21 11:28:45 +02:00
em_cmp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
em_ipset.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
em_ipt.c net: sched: em_ipt: add support for addrtype matching 2019-06-29 11:15:12 -07:00
em_meta.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
em_nbyte.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
em_text.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
em_u32.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ematch.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
Kconfig net: Fix Kconfig indentation 2019-09-26 08:56:17 +02:00
Makefile net/sched: Introduce action ct 2019-07-09 12:11:59 -07:00
sch_api.c net_sched: add max len check for TCA_KIND 2019-09-21 19:18:51 -07:00
sch_atm.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
sch_blackhole.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_cake.c netlink: make validation more configurable for future strictness 2019-04-27 17:07:21 -04:00
sch_cbq.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_cbs.c net/sched: cbs: Fix not adding cbs instance to list 2019-09-26 09:03:03 +02:00
sch_choke.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sch_codel.c net: sched: Fix a possible null-pointer dereference in dequeue_func() 2019-07-29 09:46:58 -07:00
sch_drr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sch_dsmark.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
sch_etf.c etf: Add skip_sock_check 2019-06-28 14:45:33 -07:00
sch_fifo.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_fq_codel.c fq_codel: remove set but not used variables 'prev_ecn_mark' and 'prev_drop_count' 2019-08-08 22:32:19 -07:00
sch_fq.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_generic.c net_sched: let qdisc_put() accept NULL pointer 2019-09-15 20:54:14 +02:00
sch_gred.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_hfsc.c netlink: make validation more configurable for future strictness 2019-04-27 17:07:21 -04:00
sch_hhf.c sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero 2019-09-10 18:31:00 +01:00
sch_htb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_ingress.c net: flow_offload: rename TCF_BLOCK_BINDER_TYPE_* to FLOW_BLOCK_BINDER_TYPE_* 2019-07-09 14:38:50 -07:00
sch_mq.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sch_mqprio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sch_multiq.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
sch_netem.c sch_netem: fix rcu splat in netem_enqueue() 2019-09-27 10:29:11 +02:00
sch_pie.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 235 2019-06-19 17:09:07 +02:00
sch_plug.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_prio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_qfq.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sch_red.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_sfb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sch_sfq.c net_sched: unset TCQ_F_CAN_BYPASS when adding filters 2019-07-17 13:34:09 -07:00
sch_skbprio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_taprio.c taprio: Add support for hardware offloading 2019-09-16 21:32:57 +02:00
sch_tbf.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sch_teql.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00