syzbot


INFO: rcu detected stall in sctp_generate_timeout_event

Status: auto-closed as invalid on 2022/02/03 11:46
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 366d, last: 366d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 BUG: soft lockup in sctp_generate_timeout_event C error 4 328d 503d 0/1 upstream: reported C repro on 2021/07/21 02:50

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=60f/1/0x4000000000000000 softirq=194780/194781 fqs=4838 
	(t=10502 jiffies g=353061 q=21608)
NMI backtrace for cpu 1
CPU: 1 PID: 1250 Comm: syz-executor.5 Not tainted 5.16.0-rc2-next-20211125-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+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:688 [inline]
 rcu_pending kernel/rcu/tree.c:3919 [inline]
 rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2617
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __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:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:fib_rule_match net/core/fib_rules.c:265 [inline]
RIP: 0010:fib_rules_lookup+0x13a/0xc20 net/core/fib_rules.c:302
Code: 00 00 00 00 fc ff df 49 89 c7 48 89 44 24 30 49 c1 ef 03 49 01 ef e8 f5 49 35 fa 48 8d 7b 10 48 89 f8 48 c1 e8 03 0f b6 04 28 <84> c0 74 08 3c 03 0f 8e 7f 09 00 00 44 8b 6b 10 31 ff 44 89 ee e8
RSP: 0018:ffffc90000dd0118 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffff888075d31400 RCX: 0000000000000100
RDX: ffff888153e39d40 RSI: ffffffff87429aeb RDI: ffff888075d31410
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff87429b92 R11: 0000000000000000 R12: ffffc90000dd0670
R13: 0000000000000000 R14: 0000000000000001 R15: fffff520001ba0cf
 fib6_rule_lookup+0x4ba/0x6f0 net/ipv6/fib6_rules.c:107
 ip6_route_output_flags_noref+0x2e2/0x380 net/ipv6/route.c:2627
 ip6_route_output_flags+0x72/0x320 net/ipv6/route.c:2640
 ip6_dst_lookup_tail+0xa13/0x1620 net/ipv6/ip6_output.c:1097
 ip6_dst_lookup_flow+0x8c/0x1d0 net/ipv6/ip6_output.c:1200
 sctp_v6_get_dst+0x107e/0x1d60 net/sctp/ipv6.c:385
 sctp_transport_route+0x125/0x350 net/sctp/transport.c:458
 sctp_packet_config+0xa01/0xe50 net/sctp/output.c:103
 sctp_packet_singleton+0x162/0x360 net/sctp/outqueue.c:771
 sctp_outq_flush_ctrl.constprop.0+0x5dc/0xab0 net/sctp/outqueue.c:908
 sctp_outq_flush net/sctp/outqueue.c:1202 [inline]
 sctp_outq_uncork+0x10b/0x200 net/sctp/outqueue.c:758
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1812 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1195 [inline]
 sctp_do_sm+0x745/0x4ee0 net/sctp/sm_sideeffect.c:1166
 sctp_generate_timeout_event+0x1bb/0x3d0 net/sctp/sm_sideeffect.c:295
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
 __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:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:deref_stack_reg+0xa/0x150 arch/x86/kernel/unwind_orc.c:351
Code: 24 e8 ba 7b 8e 00 48 8b 14 24 e9 48 ff ff ff 48 89 0c 24 e8 a8 7b 8e 00 48 8b 0c 24 eb 9d 66 90 48 b8 00 00 00 00 00 fc ff df <41> 55 41 54 49 89 fc 55 48 89 f5 53 48 89 d3 48 89 fa 48 c1 ea 03
RSP: 0018:ffffc9000cfc7740 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 1ffff920019f8ef1 RCX: ffffffff8e0c3ed9
RDX: ffffc9000cfc78b8 RSI: ffffc9000cfc7868 RDI: ffffc9000cfc7870
RBP: 0000000000000001 R08: ffffffff8e0c3ed4 R09: 0000000000000001
R10: fffff520019f8f19 R11: 000000000008808a R12: ffffc9000cfc78b8
R13: ffffc9000cfc78a5 R14: ffffc9000cfc7870 R15: ffffffff8e0c3ed8
 unwind_next_frame+0xcdc/0x1ce0 arch/x86/kernel/unwind_orc.c:534
 __unwind_start+0x51b/0x800 arch/x86/kernel/unwind_orc.c:712
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0x5c/0xe0 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 ____kasan_kmalloc mm/kasan/common.c:472 [inline]
 __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:590 [inline]
 kzalloc include/linux/slab.h:724 [inline]
 class_dir_create_and_add drivers/base/core.c:2939 [inline]
 get_device_parent+0x314/0x590 drivers/base/core.c:3003
 device_add+0x2a8/0x1ee0 drivers/base/core.c:3315
 cdev_device_add+0x12a/0x210 fs/char_dev.c:549
 uif_init drivers/mtd/ubi/build.c:466 [inline]
 ubi_attach_mtd_dev+0x1642/0x32c0 drivers/mtd/ubi/build.c:985
 ctrl_cdev_ioctl+0x2f0/0x390 drivers/mtd/ubi/cdev.c:1043
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 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: 0033:0x7fa656268ae9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa65519c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa65637c0f0 RCX: 00007fa656268ae9
RDX: 0000000020006000 RSI: 0000000040186f40 RDI: 0000000000000005
RBP: 00007fa6562c2ff7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffecc2e8aff R14: 00007fa65519c300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess), 7 bytes skipped:
   0:	49 89 c7             	mov    %rax,%r15
   3:	48 89 44 24 30       	mov    %rax,0x30(%rsp)
   8:	49 c1 ef 03          	shr    $0x3,%r15
   c:	49 01 ef             	add    %rbp,%r15
   f:	e8 f5 49 35 fa       	callq  0xfa354a09
  14:	48 8d 7b 10          	lea    0x10(%rbx),%rdi
  18:	48 89 f8             	mov    %rdi,%rax
  1b:	48 c1 e8 03          	shr    $0x3,%rax
  1f:	0f b6 04 28          	movzbl (%rax,%rbp,1),%eax
* 23:	84 c0                	test   %al,%al <-- trapping instruction
  25:	74 08                	je     0x2f
  27:	3c 03                	cmp    $0x3,%al
  29:	0f 8e 7f 09 00 00    	jle    0x9ae
  2f:	44 8b 6b 10          	mov    0x10(%rbx),%r13d
  33:	31 ff                	xor    %edi,%edi
  35:	44 89 ee             	mov    %r13d,%esi
  38:	e8                   	.byte 0xe8

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-linux-next-kasan-gce-root 2021/12/05 11:41 linux-next f81e94e91878 a617004c .config log report info INFO: rcu detected stall in sctp_generate_timeout_event
* Struck through repros no longer work on HEAD.