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BUG: soft lockup in sctp_generate_timeout_event

Status: upstream: reported C repro on 2021/07/21 02:50
Reported-by: syzbot+ce79b6730b4a90a87bb1@syzkaller.appspotmail.com
First crash: 1499d, last: 1324d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: soft lockup in sctp_generate_timeout_event net 1 1 119d 118d 0/29 auto-obsoleted due to no activity on 2025/08/09 02:09
upstream INFO: rcu detected stall in sctp_generate_timeout_event net 1 1 1362d 1362d 0/29 auto-closed as invalid on 2022/02/03 11:46
upstream INFO: rcu detected stall in sctp_generate_timeout_event (2) sctp 1 1 386d 386d 0/29 auto-obsoleted due to no activity on 2024/11/05 06:45
linux-6.1 INFO: rcu detected stall in sctp_generate_timeout_event 1 1 319d 319d 0/3 auto-obsoleted due to no activity on 2025/01/20 19:21
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2021/11/10 12:13 11m bisect fix linux-4.19.y error job log
2021/10/11 11:48 24m bisect fix linux-4.19.y OK (0) job log log

Sample crash report:
watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [syz-executor663:9338]
Modules linked in:
irq event stamp: 1513487
hardirqs last  enabled at (1513486): [<ffffffff8818d619>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
hardirqs last  enabled at (1513486): [<ffffffff8818d619>] _raw_spin_unlock_irqrestore+0x79/0xe0 kernel/locking/spinlock.c:184
hardirqs last disabled at (1513487): [<ffffffff81003d00>] trace_hardirqs_off_thunk+0x1a/0x1c
softirqs last  enabled at (10466): [<ffffffff88400678>] __do_softirq+0x678/0x980 kernel/softirq.c:318
softirqs last disabled at (15797): [<ffffffff81392705>] invoke_softirq kernel/softirq.c:372 [inline]
softirqs last disabled at (15797): [<ffffffff81392705>] irq_exit+0x215/0x260 kernel/softirq.c:412
CPU: 1 PID: 9338 Comm: syz-executor663 Not tainted 4.19.198-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:preempt_count_sub+0xc4/0x150 kernel/sched/core.c:3267
Code: 00 00 8b 15 de 6b f5 0b 85 d2 75 bd 48 c7 c6 80 ba 69 88 48 c7 c7 c0 ba 69 88 e8 37 d8 b0 06 0f 0b 5b c3 65 8b 05 8c 73 c0 7e <84> c0 75 8b e8 d3 f0 31 02 85 c0 74 92 48 c7 c0 40 d7 36 8d 48 ba
RSP: 0018:ffff8880ba106de0 EFLAGS: 00000297 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000102 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff83772831 RDI: 0000000000000001
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffffffff89f88200
R13: ffffffff89f88200 R14: ffff8880ba106ec8 R15: 0000000000000001
FS:  00007fd572fdf700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000485c00 CR3: 000000009e915000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1081 [inline]
 rcu_lockdep_current_cpu_online+0x12f/0x1b0 kernel/rcu/tree.c:1068
 rcu_read_lock_held+0xc3/0x110 kernel/rcu/update.c:285
 fib6_node_lookup_1+0x739/0x910 net/ipv6/ip6_fib.c:1415
 fib6_node_lookup+0xbe/0x170 net/ipv6/ip6_fib.c:1485
 fib6_table_lookup+0xb3/0xf40 net/ipv6/route.c:1869
 ip6_pol_route+0x180/0x1270 net/ipv6/route.c:1909
 fib6_rule_lookup+0x10b/0x4e0 net/ipv6/fib6_rules.c:118
 ip6_route_output_flags+0x2b0/0x350 net/ipv6/route.c:2163
 ip6_route_output include/net/ip6_route.h:88 [inline]
 ip6_dst_lookup_tail+0x104d/0x19b0 net/ipv6/ip6_output.c:990
 ip6_dst_lookup_flow+0x8c/0x1d0 net/ipv6/ip6_output.c:1118
 sctp_v6_get_dst+0x69f/0x1c90 net/sctp/ipv6.c:291
 sctp_transport_route+0x125/0x350 net/sctp/transport.c:312
 sctp_packet_config+0xbd8/0xe50 net/sctp/output.c:118
 sctp_outq_select_transport+0x1e4/0x740 net/sctp/outqueue.c:878
 sctp_outq_flush_ctrl.constprop.0+0x291/0xc40 net/sctp/outqueue.c:912
 sctp_outq_flush net/sctp/outqueue.c:1205 [inline]
 sctp_outq_uncork+0x10b/0x200 net/sctp/outqueue.c:777
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1815 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline]
 sctp_do_sm+0x72a/0x5110 net/sctp/sm_sideeffect.c:1170
 sctp_generate_timeout_event+0x1bb/0x3a0 net/sctp/sm_sideeffect.c:310
 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338
 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375
 __run_timers kernel/time/timer.c:1696 [inline]
 run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709
 __do_softirq+0x265/0x980 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x215/0x260 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0010:qlink_to_object mm/kasan/quarantine.c:136 [inline]
RIP: 0010:qlink_free mm/kasan/quarantine.c:141 [inline]
RIP: 0010:qlist_free_all+0x32/0x140 mm/kasan/quarantine.c:166
Code: 55 53 48 8b 1f 48 85 db 0f 84 08 01 00 00 48 89 f5 49 89 fd 48 85 ed 49 89 ee 0f 84 8b 00 00 00 49 63 86 fc 00 00 00 4c 8b 23 <48> 29 c3 48 83 3d 93 21 59 08 00 0f 84 e6 00 00 00 9c 58 0f 1f 44
RSP: 0018:ffff88809ee27530 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff88809e145200 RCX: ffffea0002785100
RDX: 0000000000000001 RSI: ffffffff812b5e9a RDI: 0000000000000007
RBP: 0000000000000000 R08: ffffed1013c17a00 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000000 R12: ffff88809dc55dc0
R13: ffff88809ee27568 R14: ffff88813bff0ac0 R15: 0000000000000282
 quarantine_reduce+0x1a9/0x230 mm/kasan/quarantine.c:259
 kasan_kmalloc+0xa2/0x160 mm/kasan/kasan.c:538
 kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 sctp_transport_new+0x71/0x710 net/sctp/transport.c:111
 sctp_assoc_add_peer+0x2a6/0x1050 net/sctp/associola.c:636
 sctp_sendmsg_new_asoc+0x580/0x1040 net/sctp/socket.c:1789
 sctp_sendmsg+0x1146/0x1580 net/sctp/socket.c:2122
 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:661
 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2225
 __sys_sendmsg net/socket.c:2263 [inline]
 __do_sys_sendmsg net/socket.c:2272 [inline]
 __se_sys_sendmsg net/socket.c:2270 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2270
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x445819
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 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:00007fd572fdf318 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004ca408 RCX: 0000000000445819
RDX: 0000000000000000 RSI: 0000000020001400 RDI: 0000000000000003
RBP: 00000000004ca400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004ca40c
R13: 00007fffdc05205f R14: 00007fd572fdf400 R15: 0000000000022000

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/07/21 02:49 linux-4.19.y 4938296e03bd 1b201b48 .config console log report syz C ci2-linux-4-19 BUG: soft lockup in sctp_generate_timeout_event
2022/01/12 05:54 linux-4.19.y 3f8a27f9e27b 44d1319a .config console log report info ci2-linux-4-19 BUG: soft lockup in sctp_generate_timeout_event
2021/09/11 11:48 linux-4.19.y b172b44fcb17 3ce60af8 .config console log report info ci2-linux-4-19 BUG: soft lockup in sctp_generate_timeout_event
2021/08/14 22:13 linux-4.19.y addba38e7c3b 2489ab88 .config console log report info ci2-linux-4-19 BUG: soft lockup in sctp_generate_timeout_event
* Struck through repros no longer work on HEAD.