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INFO: rcu detected stall in tcp_setsockopt (3)

Status: upstream: reported on 2026/05/25 18:14
Reported-by: syzbot+485ab36ce0cc9e2b8859@syzkaller.appspotmail.com
First crash: 21d, last: 1d01h
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in tcp_setsockopt 1 1 718d 718d 0/3 auto-obsoleted due to no activity on 2024/10/05 09:05
linux-5.15 INFO: rcu detected stall in tcp_setsockopt (2) 1 2 222d 234d 0/3 auto-obsoleted due to no activity on 2026/02/13 03:22
upstream INFO: rcu detected stall in tcp_setsockopt netfilter 1 syz error error 4 440d 1021d 0/29 auto-obsoleted due to no activity on 2025/07/30 15:19
android-49 INFO: rcu detected stall in tcp_setsockopt 1 2 2613d 2619d 0/3 auto-closed as invalid on 2019/10/17 00:42
android-5-15 BUG: soft lockup in tcp_setsockopt 1 1 773d 773d 0/2 auto-obsoleted due to no activity on 2024/08/01 04:54

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=849/1/0x4000000000000000 softirq=52694/52695 fqs=20 
	(detected by 1, t=10502 jiffies, g=80381, q=393)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15022 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline]
RIP: 0010:kasan_check_range+0xe/0x290 mm/kasan/generic.c:189
Code: 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 00 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 ac 01 00 00 55 41 57 <41> 56 41 54 53 49 89 f8 49 01 f0 0f 82 0e 02 00 00 49 89 f8 49 c1
RSP: 0018:ffffc900000078e8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 00000000000000bc RCX: ffffffff815d3d48
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d80d0
RBP: ffffc90000007b50 R08: dffffc0000000000 R09: 1ffffffff203b01a
R10: dffffc0000000000 R11: fffffbfff203b01b R12: 0000000099b9b75a
R13: ffff88807b781dc0 R14: 00000000eab6f266 R15: ffff88807b7828d0
FS:  0000555592cd6500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001100 CR3: 0000000022f20000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 hlock_class kernel/locking/lockdep.c:197 [inline]
 __lock_acquire+0x12e8/0x7d10 kernel/locking/lockdep.c:5009
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0xab/0xf0 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
 __hrtimer_run_queues+0x5a9/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
Code: be ff ff ff ff e8 4c ee 68 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 f6 59 72 08 e8 f1 e6 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c
RSP: 0018:ffffc90002ecf1a8 EFLAGS: 00000282
RAX: d2c8d8c21f75ef00 RBX: ffff8880b903a340 RCX: d2c8d8c21f75ef00
RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: ffffffff8a7a09c0
RBP: 1ffff11017207613 R08: ffff8880b903a343 R09: 1ffff11017207468
R10: dffffc0000000000 R11: ffffed1017207469 R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
 finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
 context_switch kernel/sched/core.c:5052 [inline]
 __schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6596
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
 _raw_spin_unlock_irqrestore+0x10d/0x120 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:419 [inline]
 free_percpu+0x86e/0xd70 mm/percpu.c:2308
 cleanup_entry+0x2ba/0x340 net/ipv4/netfilter/ip_tables.c:655
 __do_replace+0x73d/0x9b0 net/ipv4/netfilter/ip_tables.c:1083
 do_replace net/ipv4/netfilter/ip_tables.c:1142 [inline]
 do_ipt_set_ctl+0xaa1/0xd80 net/ipv4/netfilter/ip_tables.c:1636
 nf_setsockopt+0x25f/0x280 net/netfilter/nf_sockopt.c:101
 ip_setsockopt+0x207d/0x3130 net/ipv4/ip_sockglue.c:1442
 tcp_setsockopt+0x240/0x1e90 net/ipv4/tcp.c:3722
 __sys_setsockopt+0x2bf/0x3d0 net/socket.c:2212
 __do_sys_setsockopt net/socket.c:2223 [inline]
 __se_sys_setsockopt net/socket.c:2220 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2220
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f736a4ab69a
Code: 48 83 ec 10 48 63 c9 48 63 ff 45 89 c9 6a 2c e8 6c 99 fb ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 49 89 ca b8 36 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7
RSP: 002b:00007ffefafea198 EFLAGS: 00000202 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007ffefafea220 RCX: 00007f736a4ab69a
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00000000000002d8 R09: 0000000000000000
R10: 00007f736a6f8020 R11: 0000000000000202 R12: 00007f736a6f7fc0
R13: 00007ffefafea1bc R14: 0000000000000000 R15: 00007f736a6fa180
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10461 jiffies! g80381 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=43061
rcu: rcu_preempt kthread starved for 10462 jiffies! g80381 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:27536 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 16368 Comm: syz.3.3037 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x1110/0x1270 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x843/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xbb5/0xd90 kernel/smp.c:969
Code: b6 44 05 00 84 c0 0f 85 9d 00 00 00 41 8b 1c 24 89 de 83 e6 01 31 ff e8 d9 62 0b 00 83 e3 01 75 07 e8 6f 5f 0b 00 eb 43 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 11 41 f7
RSP: 0018:ffffc9000406f8e0 EFLAGS: 00000202
RAX: ffffffff816de9a8 RBX: 0000000000000001 RCX: ffff88806107bb80
RDX: 0000000000000003 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000406fa20 R08: 00000000000326c0 R09: 0000000000400000
R10: 00000000000326e8 R11: fffffbfff203b04a R12: ffff8880b9042848
R13: 1ffff11017208509 R14: ffff8880b913b3c0 R15: 0000000000000000
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1134
 kill_bdev block/bdev.c:76 [inline]
 set_blocksize+0x2ed/0x370 block/bdev.c:157
 sb_set_blocksize block/bdev.c:166 [inline]
 sb_min_blocksize+0xdc/0x1a0 block/bdev.c:182
 isofs_fill_super+0x8dc/0x26a0 fs/isofs/inode.c:658
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f83680ec0ca
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8366343e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8366343ee0 RCX: 00007f83680ec0ca
RDX: 0000200000000000 RSI: 0000200000000080 RDI: 00007f8366343ea0
RBP: 0000200000000000 R08: 00007f8366343ee0 R09: 0000000000000445
R10: 0000000000000445 R11: 0000000000000246 R12: 0000200000000080
R13: 00007f8366343ea0 R14: 0000000000000672 R15: 0000200000000940
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/14 21:05 linux-5.15.y dc027a595035 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in tcp_setsockopt
2026/05/25 18:14 linux-5.15.y 241d66fa280c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in tcp_setsockopt
* Struck through repros no longer work on HEAD.