syzbot


possible deadlock in sch_direct_xmit

Status: auto-obsoleted due to no activity on 2023/08/23 09:09
Reported-by: syzbot+df49c4b28f24568bf8cc@syzkaller.appspotmail.com
First crash: 350d, last: 350d
Similar bugs (11)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 possible deadlock in sch_direct_xmit (2) C 9 14d 106d 0/3 upstream: reported C repro on 2024/01/09 18:28
android-44 possible deadlock in sch_direct_xmit C 240 1604d 1841d 0/2 public: reported C repro on 2019/04/11 08:44
upstream possible deadlock in sch_direct_xmit (2) net C done unreliable 109 283d 1457d 0/26 auto-obsoleted due to no activity on 2024/01/14 06:05
linux-4.19 possible deadlock in sch_direct_xmit (2) C error 15 425d 942d 0/1 upstream: reported C repro on 2021/09/26 01:30
upstream possible deadlock in sch_direct_xmit net C done done 1548 1612d 2290d 15/26 fixed on 2020/04/17 19:57
linux-5.15 possible deadlock in sch_direct_xmit (2) 4 1d02h 62d 0/3 upstream: reported on 2024/02/22 19:25
linux-4.14 possible deadlock in sch_direct_xmit 1 1788d 1788d 0/1 auto-closed as invalid on 2019/10/25 08:40
linux-4.14 possible deadlock in sch_direct_xmit (2) 1 1621d 1621d 0/1 auto-closed as invalid on 2020/03/15 19:58
linux-4.19 possible deadlock in sch_direct_xmit 1 1789d 1789d 0/1 auto-closed as invalid on 2019/10/25 08:50
linux-6.1 possible deadlock in sch_direct_xmit 2 357d 396d 0/3 auto-obsoleted due to no activity on 2023/08/23 09:10
upstream possible deadlock in sch_direct_xmit (3) net 1 73d 73d 26/26 fixed on 2024/04/10 16:40

Sample crash report:
============================================
WARNING: possible recursive locking detected
5.15.110-syzkaller #0 Not tainted
--------------------------------------------
sed/10883 is trying to acquire lock:
ffff888147800218 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline]
ffff888147800218 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4429 [inline]
ffff888147800218 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340

but task is already holding lock:
ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline]
ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4429 [inline]
ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(_xmit_ETHER#2);
  lock(_xmit_ETHER#2);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

8 locks held by sed/10883:
 #0: ffffc90000dd0be0 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline]
 #0: ffffc90000dd0be0 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x560 kernel/time/timer.c:1411
 #1: ffffffff8c91c540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:269
 #2: ffffffff8c91c540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:269
 #3: ffff8880243f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:373 [inline]
 #3: ffff8880243f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:173 [inline]
 #3: ffff8880243f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3806 [inline]
 #3: ffff8880243f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x11f2/0x3230 net/core/dev.c:4188
 #4: ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline]
 #4: ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4429 [inline]
 #4: ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340
 #5: ffffffff8c91c540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:269
 #6: ffffffff8c91c540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:269
 #7: ffff88801b1ab258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:373 [inline]
 #7: ffff88801b1ab258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:173 [inline]
 #7: ffff88801b1ab258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3806 [inline]
 #7: ffff88801b1ab258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x11f2/0x3230 net/core/dev.c:4188

stack backtrace:
CPU: 1 PID: 10883 Comm: sed Not tainted 5.15.110-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2946 [inline]
 check_deadlock kernel/locking/lockdep.c:2989 [inline]
 validate_chain+0x46cf/0x58b0 kernel/locking/lockdep.c:3774
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:363 [inline]
 __netif_tx_lock include/linux/netdevice.h:4429 [inline]
 sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340
 __dev_xmit_skb net/core/dev.c:3819 [inline]
 __dev_queue_xmit+0x18ee/0x3230 net/core/dev.c:4188
 neigh_output include/net/neighbour.h:516 [inline]
 ip_finish_output2+0xdbe/0x1270 net/ipv4/ip_output.c:228
 iptunnel_xmit+0x50c/0x960 net/ipv4/ip_tunnel_core.c:82
 ip_tunnel_xmit+0x1c55/0x24a0 net/ipv4/ip_tunnel.c:810
 __gre_xmit net/ipv4/ip_gre.c:469 [inline]
 erspan_xmit+0xa9c/0x1530 net/ipv4/ip_gre.c:715
 __netdev_start_xmit include/linux/netdevice.h:5019 [inline]
 netdev_start_xmit include/linux/netdevice.h:5033 [inline]
 xmit_one net/core/dev.c:3592 [inline]
 dev_hard_start_xmit+0x298/0x7a0 net/core/dev.c:3608
 sch_direct_xmit+0x2b2/0x5e0 net/sched/sch_generic.c:342
 __dev_xmit_skb net/core/dev.c:3819 [inline]
 __dev_queue_xmit+0x18ee/0x3230 net/core/dev.c:4188
 neigh_output include/net/neighbour.h:516 [inline]
 ip_finish_output2+0xdbe/0x1270 net/ipv4/ip_output.c:228
 igmpv3_send_cr net/ipv4/igmp.c:720 [inline]
 igmp_ifc_timer_expire+0xaa3/0xf60 net/ipv4/igmp.c:810
 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1737
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750
 __do_softirq+0x3b3/0x93a kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 02 b8 a5 f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> e7 92 33 f7 65 8b 05 f8 ee de 75 85 c0 74 3f 48 c7 04 24 0e 36
RSP: 0018:ffffc900052cfcc0 EFLAGS: 00000206
RAX: 110dd6943c429900 RBX: 1ffff92000a59f9c RCX: ffffffff913be003
RDX: dffffc0000000000 RSI: ffffffff8a8afb60 RDI: 0000000000000001
RBP: ffffc900052cfd50 R08: ffffffff81864ef0 R09: fffffbfff22afbc0
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000a59f98 R14: ffffc900052cfce0 R15: 0000000000000246
 debug_rcu_head_queue kernel/rcu/rcu.h:177 [inline]
 __call_rcu kernel/rcu/tree.c:2977 [inline]
 call_rcu+0xb1/0xa70 kernel/rcu/tree.c:3073
 task_work_run+0x129/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:175
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f33b155ea46
Code: 10 00 00 00 44 8b 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 44 89 c2 4c 89 ce bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 0c f7 d8 89 05 0a 48 01 00 48 83 c8 ff c3 31
RSP: 002b:00007ffcd8563a08 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: fffffffffffffffe RBX: 00007ffcd8563c68 RCX: 00007f33b155ea46
RDX: 0000000000080000 RSI: 00007ffcd8563a80 RDI: 00000000ffffff9c
RBP: 00007ffcd8563a70 R08: 0000000000080000 R09: 00007ffcd8563a80
R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffcd8563a80
R13: 0000000000000009 R14: 00007ffcd8563c4f R15: 00000000ffffffff
 </TASK>
----------------
Code disassembly (best guess):
   0:	9c                   	pushfq
   1:	8f 44 24 20          	popq   0x20(%rsp)
   5:	42 80 3c 23 00       	cmpb   $0x0,(%rbx,%r12,1)
   a:	74 08                	je     0x14
   c:	4c 89 f7             	mov    %r14,%rdi
   f:	e8 02 b8 a5 f7       	callq  0xf7a5b816
  14:	f6 44 24 21 02       	testb  $0x2,0x21(%rsp)
  19:	75 4e                	jne    0x69
  1b:	41 f7 c7 00 02 00 00 	test   $0x200,%r15d
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 e7 92 33 f7       	callq  0xf7339316 <-- trapping instruction
  2f:	65 8b 05 f8 ee de 75 	mov    %gs:0x75deeef8(%rip),%eax        # 0x75deef2e
  36:	85 c0                	test   %eax,%eax
  38:	74 3f                	je     0x79
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/11 12:28 linux-5.15.y 8a7f2a5c5aa1 0fbd49f4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in sch_direct_xmit
* Struck through repros no longer work on HEAD.