syzbot


INFO: rcu detected stall in v4l2_ioctl

Status: auto-closed as invalid on 2022/06/24 20:18
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 221d, last: 221d

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=6df/1/0x4000000000000000 softirq=8192/8192 fqs=0 
	(t=10500 jiffies g=7213 q=35 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g7213 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=2526
rcu: rcu_preempt kthread starved for 10500 jiffies! g7213 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:29264 pid:   16 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5106 [inline]
 __schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
 schedule+0xd2/0x1f0 kernel/sched/core.c:6493
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1907
 rcu_gp_fqs_loop+0x1c0/0x840 kernel/rcu/tree.c:2078
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2267
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4331 Comm: syz-executor.1 Not tainted 5.18.0-rc3-next-20220422-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kvm_wait+0x98/0x100 arch/x86/kernel/kvm.c:1058
Code: fa 83 e2 07 38 d0 7f 04 84 c0 75 63 0f b6 07 40 38 c6 74 35 48 83 c4 10 c3 c3 e8 23 91 4b 00 eb 07 0f 00 2d da b1 94 08 fb f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 56 8f 4b 00 8b 74 24 0c
RSP: 0018:ffffc900000070d8 EFLAGS: 00000246
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 1ffffffff1b73199
RDX: 0000000000000000 RSI: ffffffff81807171 RDI: ffffffff8134dffd
RBP: ffff88801d3fc448 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81807158 R11: 0000000000000001 R12: 0000000000000000
R13: ffffed1003a7f889 R14: 0000000000000001 R15: ffff8880b9c3ae40
FS:  00007fcba0271700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020040030 CR3: 0000000075c3f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x8c7/0xb50 kernel/locking/qspinlock.c:511
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x200/0x2a0 kernel/locking/spinlock_debug.c:115
 spin_lock include/linux/spinlock.h:354 [inline]
 task_lock include/linux/sched/task.h:170 [inline]
 __get_task_comm+0x23/0x50 fs/exec.c:1219
 __set_page_owner_handle mm/page_owner.c:174 [inline]
 __set_page_owner+0x253/0x380 mm/page_owner.c:192
 prep_new_page mm/page_alloc.c:2394 [inline]
 get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4135
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5356
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2273
 alloc_slab_page mm/slub.c:1797 [inline]
 allocate_slab+0x26c/0x3c0 mm/slub.c:1942
 new_slab mm/slub.c:2002 [inline]
 ___slab_alloc+0x985/0xd90 mm/slub.c:3002
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3089
 slab_alloc_node mm/slub.c:3180 [inline]
 kmem_cache_alloc_node+0x122/0x3f0 mm/slub.c:3264
 __alloc_skb+0x215/0x340 net/core/skbuff.c:414
 alloc_skb include/linux/skbuff.h:1337 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 __neigh_notify+0x84/0x160 net/core/neighbour.c:3459
 neigh_cleanup_and_release+0x92/0x340 net/core/neighbour.c:101
 neigh_del net/core/neighbour.c:225 [inline]
 neigh_remove_one+0x37d/0x460 net/core/neighbour.c:246
 neigh_forced_gc net/core/neighbour.c:276 [inline]
 neigh_alloc net/core/neighbour.c:423 [inline]
 ___neigh_create+0x18b1/0x2990 net/core/neighbour.c:618
 ip6_finish_output2+0x1079/0x1500 net/ipv6/ip6_output.c:123
 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
 __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170
 ip6_finish_output+0x32/0x280 net/ipv6/ip6_output.c:201
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224
 dst_output include/net/dst.h:451 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ndisc_send_skb+0xa89/0x17e0 net/ipv6/ndisc.c:507
 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:717
 addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3931
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1444
 expire_timers kernel/time/timer.c:1489 [inline]
 __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1760
 __run_timers kernel/time/timer.c:1738 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1773
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:strscpy_pad+0x46/0x70 lib/string_helpers.c:789
Code: 60 c9 24 00 31 ff 49 89 c4 48 89 c6 e8 e3 7c 7f fd 4d 85 e4 78 30 e8 49 7a 7f fd 48 83 eb 01 4c 89 e6 48 89 df e8 aa 7d 7f fd <4c> 39 e3 74 17 e8 30 7a 7f fd 4a 8d 7c 25 01 4c 29 e3 31 f6 48 89
RSP: 0018:ffffc9000431f458 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 000000000000000f RCX: 000000000000000e
RDX: 0000000000000000 RSI: ffff88801d3fbb00 RDI: 0000000000000003
RBP: ffff888012d8b2e8 R08: 000000000000000f R09: ffff88801d3fc338
R10: ffffffff83faa4e6 R11: 0000000000000001 R12: 000000000000000e
R13: 0000000000000010 R14: ffff888012d8b2c8 R15: 0000000000000007
 __get_task_comm+0x35/0x50 fs/exec.c:1221
 __set_page_owner_handle mm/page_owner.c:174 [inline]
 __set_page_owner+0x253/0x380 mm/page_owner.c:192
 prep_new_page mm/page_alloc.c:2394 [inline]
 get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4135
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5356
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2273
 vm_area_alloc_pages mm/vmalloc.c:2931 [inline]
 __vmalloc_area_node mm/vmalloc.c:2990 [inline]
 __vmalloc_node_range+0x8a7/0x13c0 mm/vmalloc.c:3161
 vmalloc_user+0x67/0x80 mm/vmalloc.c:3315
 vb2_vmalloc_alloc+0x11e/0x3f0 drivers/media/common/videobuf2/videobuf2-vmalloc.c:47
 __vb2_buf_mem_alloc drivers/media/common/videobuf2/videobuf2-core.c:233 [inline]
 __vb2_queue_alloc+0x60b/0x1180 drivers/media/common/videobuf2/videobuf2-core.c:444
 vb2_core_reqbufs+0x7e5/0xd70 drivers/media/common/videobuf2/videobuf2-core.c:838
 vb2_reqbufs+0x1a3/0x200 drivers/media/common/videobuf2/videobuf2-v4l2.c:719
 v4l2_m2m_reqbufs drivers/media/v4l2-core/v4l2-mem2mem.c:578 [inline]
 v4l2_m2m_ioctl_reqbufs+0xda/0x220 drivers/media/v4l2-core/v4l2-mem2mem.c:1366
 v4l_reqbufs drivers/media/v4l2-core/v4l2-ioctl.c:2034 [inline]
 v4l_reqbufs+0xa2/0xd0 drivers/media/v4l2-core/v4l2-ioctl.c:2023
 __video_do_ioctl+0xb94/0xe20 drivers/media/v4l2-core/v4l2-ioctl.c:2981
 video_usercopy+0x3ab/0x16c0 drivers/media/v4l2-core/v4l2-ioctl.c:3329
 v4l2_ioctl+0x1b3/0x250 drivers/media/v4l2-core/v4l2-dev.c:364
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fcb9f0890e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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:00007fcba0271168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcb9f19c030 RCX: 00007fcb9f0890e9
RDX: 00000000200000c0 RSI: 00000000c0145608 RDI: 0000000000000003
RBP: 00007fcb9f0e308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe5a1b540f R14: 00007fcba0271300 R15: 0000000000022000
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 4326 Comm: syz-executor.4 Not tainted 5.18.0-rc3-next-20220422-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x262/0x3f0 kernel/rcu/tree_stall.h:369
 print_cpu_stall kernel/rcu/tree_stall.h:665 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:749 [inline]
 rcu_pending kernel/rcu/tree.c:4068 [inline]
 rcu_sched_clock_irq.cold+0x144/0x8fc kernel/rcu/tree.c:2755
 update_process_times+0x16d/0x200 kernel/time/timer.c:1811
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243
 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:queued_write_lock_slowpath+0x143/0x2d0 kernel/locking/qrwlock.c:85
Code: 00 00 00 fc ff df 49 01 c7 41 83 c6 03 41 0f b6 07 41 38 c6 7c 08 84 c0 0f 85 46 01 00 00 8b 45 00 3d 00 01 00 00 74 19 f3 90 <41> 0f b6 07 41 38 c6 7c eb 84 c0 74 e7 48 89 ef e8 e8 f7 67 00 eb
RSP: 0018:ffffc90000de0718 EFLAGS: 00000206
RAX: 00000000000001ff RBX: 1ffff920001bc0e4 RCX: ffffffff815eb279
RDX: fffffbfff1ae56f8 RSI: 0000000000000004 RDI: ffffffff8d72b7b8
RBP: ffffffff8d72b7b8 R08: 0000000000000001 R09: ffffffff8d72b7bb
R10: fffffbfff1ae56f7 R11: 0000000000000000 R12: ffffffff8d72b7bc
R13: 00000000000000ff R14: 0000000000000003 R15: fffffbfff1ae56f7
 queued_write_lock include/asm-generic/qrwlock.h:97 [inline]
 do_raw_write_lock+0x1ce/0x280 kernel/locking/spinlock_debug.c:210
 neigh_forced_gc net/core/neighbour.c:261 [inline]
 neigh_alloc net/core/neighbour.c:423 [inline]
 ___neigh_create+0x114b/0x2990 net/core/neighbour.c:618
 ip6_finish_output2+0x1079/0x1500 net/ipv6/ip6_output.c:123
 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
 __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170
 ip6_finish_output+0x32/0x280 net/ipv6/ip6_output.c:201
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224
 dst_output include/net/dst.h:451 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ndisc_send_skb+0xa89/0x17e0 net/ipv6/ndisc.c:507
 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:717
 addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3931
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1444
 expire_timers kernel/time/timer.c:1489 [inline]
 __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1760
 __run_timers kernel/time/timer.c:1738 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1773
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:finish_task_switch.isra.0+0x323/0xb80 kernel/sched/core.c:4986
Code: 13 eb 1b 08 85 c0 75 02 0f 0b 48 85 db 0f 85 25 01 00 00 4c 89 f7 e8 fc f7 ff ff e8 d7 44 2e 00 fb 65 48 8b 1c 25 00 70 02 00 <48> 8d bb 88 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc9001369f680 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffff88802403bb00 RCX: 1ffffffff1b73199
RDX: 0000000000000000 RSI: ffffffff81807171 RDI: ffffffff81522c49
RBP: ffffc9001369f6c8 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81807158 R11: 0000000000000001 R12: ffff8880b9d3ad58
R13: ffff88807551bb00 R14: ffff8880b9d3a000 R15: ffff8880b9d3aa38
 context_switch kernel/sched/core.c:5109 [inline]
 __schedule+0xaa2/0x4cc0 kernel/sched/core.c:6421
 schedule+0xd2/0x1f0 kernel/sched/core.c:6493
 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1883
 netlink_attachskb+0x644/0x880 net/netlink/af_netlink.c:1243
 netlink_unicast+0x1ec/0x7f0 net/netlink/af_netlink.c:1354
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 sock_write_iter+0x283/0x3c0 net/socket.c:1061
 call_write_iter include/linux/fs.h:2059 [inline]
 new_sync_write+0x38a/0x560 fs/read_write.c:504
 vfs_write+0x7c0/0xac0 fs/read_write.c:591
 ksys_write+0x1e8/0x250 fs/read_write.c:644
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f29714890e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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:00007f29726bd168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f297159bf60 RCX: 00007f29714890e9
RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00007f29714e308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe5ea65d3f R14: 00007f29726bd300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	fa                   	cli
   1:	83 e2 07             	and    $0x7,%edx
   4:	38 d0                	cmp    %dl,%al
   6:	7f 04                	jg     0xc
   8:	84 c0                	test   %al,%al
   a:	75 63                	jne    0x6f
   c:	0f b6 07             	movzbl (%rdi),%eax
   f:	40 38 c6             	cmp    %al,%sil
  12:	74 35                	je     0x49
  14:	48 83 c4 10          	add    $0x10,%rsp
  18:	c3                   	retq
  19:	c3                   	retq
  1a:	e8 23 91 4b 00       	callq  0x4b9142
  1f:	eb 07                	jmp    0x28
  21:	0f 00 2d da b1 94 08 	verw   0x894b1da(%rip)        # 0x894b202
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	48 83 c4 10          	add    $0x10,%rsp <-- trapping instruction
  2e:	c3                   	retq
  2f:	89 74 24 0c          	mov    %esi,0xc(%rsp)
  33:	48 89 3c 24          	mov    %rdi,(%rsp)
  37:	e8 56 8f 4b 00       	callq  0x4b8f92
  3c:	8b 74 24 0c          	mov    0xc(%rsp),%esi

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-linux-next-kasan-gce-root 2022/04/25 20:11 linux-next e7d6987e09a3 152baedd .config log report info INFO: rcu detected stall in v4l2_ioctl
* Struck through repros no longer work on HEAD.