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INFO: rcu detected stall in tcp_setsockopt (2)

Status: upstream: reported on 2025/10/24 16:13
Reported-by: syzbot+f22588aec1b5b574aae2@syzkaller.appspotmail.com
First crash: 28d, last: 17d
▶ ▼ Similar bugs (4)
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 513d 513d 0/3 auto-obsoleted due to no activity on 2024/10/05 09:05
upstream INFO: rcu detected stall in tcp_setsockopt netfilter 1 syz error error 4 235d 816d 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 2408d 2414d 0/3 auto-closed as invalid on 2019/10/17 00:42
android-5-15 BUG: soft lockup in tcp_setsockopt 1 1 568d 568d 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: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5687/1:b..l
	(detected by 1, t=10502 jiffies, g=44205, q=518)
task:syz-executor    state:R  running task     stack:21408 pid: 5687 ppid:  5674 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc9000315ed40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: bec851574bc5cd00
RDX: 0000000000000000 RSI: ffffffff8a0b2f00 RDI: ffffffff8a59e580
RBP: ffffc9000315ee60 R08: dffffc0000000000 R09: fffffbfff1ff7c19
R10: fffffbfff1ff7c19 R11: 1ffffffff1ff7c18 R12: ffffffff8c11c760
R13: 1ffff9200062bdb4 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725
 kernel_text_address kernel/extable.c:151 [inline]
 __kernel_text_address+0x9a/0x100 kernel/extable.c:105
 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 xt_free_table_info+0x145/0x190 net/netfilter/x_tables.c:1209
 __do_replace+0x7bf/0x9b0 net/ipv6/netfilter/ip6_tables.c:1103
 do_replace net/ipv6/netfilter/ip6_tables.c:1160 [inline]
 do_ip6t_set_ctl+0xa0d/0xd00 net/ipv6/netfilter/ip6_tables.c:1646
 nf_setsockopt+0x25f/0x280 net/netfilter/nf_sockopt.c:101
 ipv6_setsockopt+0x1cb8/0x3890 net/ipv6/ipv6_sockglue.c:1014
 tcp_setsockopt+0x21a/0x1d70 net/ipv4/tcp.c:3719
 __sys_setsockopt+0x2bf/0x3d0 net/socket.c:2213
 __do_sys_setsockopt net/socket.c:2224 [inline]
 __se_sys_setsockopt net/socket.c:2221 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2221
 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: 0033:0x7f76facd95ba
RSP: 002b:00007ffe8ffb7c48 EFLAGS: 00000206 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007ffe8ffb7cd0 RCX: 00007f76facd95ba
RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00000000000002e8 R09: 0079746972756365
R10: 00007f76faefc140 R11: 0000000000000206 R12: 00007f76faefc0e0
R13: 00007ffe8ffb7c6c R14: 0000000000000000 R15: 00007f76faefce60
 </TASK>
rcu: rcu_preempt kthread starved for 9687 jiffies! g44205 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:27880 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 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: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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+0x10c8/0x1220 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+0x831/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 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+0x4fe/0xc40 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:default_idle+0xb/0x10 arch/x86/kernel/process.c:730
Code: bf 48 89 df e8 66 76 09 f8 eb b5 e8 9f af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 37 06 53 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffc90000d67d48 EFLAGS: 000002c2
RAX: f6d87706d7a5ec00 RBX: ffff88813fe48000 RCX: f6d87706d7a5ec00
RDX: 0000000000000001 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90000d67e80 R08: dffffc0000000000 R09: ffffed1017227662
R10: ffffed1017227662 R11: 1ffff11017227661 R12: ffffffff8d699d28
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11027fc9000
 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x21b/0x5b0 kernel/sched/idle.c:306
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
 start_secondary+0x31f/0x430 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/05 03:21 linux-5.15.y cc5ec8769306 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in tcp_setsockopt
2025/10/24 16:12 linux-5.15.y ac56c046adf4 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in tcp_setsockopt
* Struck through repros no longer work on HEAD.