syzbot


INFO: rcu detected stall in sys_recvmsg

Status: upstream: reported on 2025/08/10 06:16
Reported-by: syzbot+624e0eff6200cf7fb62e@syzkaller.appspotmail.com
First crash: 279d, last: 13d
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in sys_recvmsg 1 1 303d 303d 0/3 auto-obsoleted due to no activity on 2025/10/25 13:40
linux-6.6 INFO: rcu detected stall in sys_recvmsg 1 2 262d 262d 0/2 auto-obsoleted due to no activity on 2025/12/05 18:53
android-5-15 BUG: soft lockup in sys_recvmsg 1 10 694d 781d 0/2 auto-obsoleted due to no activity on 2024/09/19 17:52
android-5-10 BUG: soft lockup in sys_recvmsg (2) 1 C error 2 209d 388d 0/2 auto-obsoleted due to no activity on 2026/01/28 03:20
android-5-10 BUG: soft lockup in sys_recvmsg 1 4 678d 757d 0/2 auto-obsoleted due to no activity on 2024/10/05 13:04

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 ticks this GP) idle=955/1/0x4000000000000002 softirq=12580/12580 fqs=2098 
	(detected by 1, t=10503 jiffies, g=15777, q=2392)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6477 Comm: syz.3.591 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:lock_acquire+0x30/0x400 kernel/locking/lockdep.c:5591
Code: 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00 4c 89 4c 24 20 4c 89 44 24 30 48 89 4c 24 28 89 d3 89 74 24 1c 49 89 fc <65> 48 8b 04 25 28 00 00 00 48 89 84 24 c0 00 00 00 49 bf 00 00 00
RSP: 0018:ffffc90000007340 EFLAGS: 00000082
RAX: ffffffff819c23fa RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c31eb20
RBP: ffffc90000007460 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1b13e06 R12: ffffffff8c31eb20
R13: ffffc90000007600 R14: 0000000000000028 R15: dffffc0000000000
FS:  00007f0c9765e6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000335000 CR3: 0000000056d35000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 __perf_output_begin kernel/events/ring_buffer.c:163 [inline]
 perf_output_begin_forward+0xa5/0xa40 kernel/events/ring_buffer.c:271
 __perf_event_output kernel/events/core.c:7804 [inline]
 perf_event_output_forward+0x19b/0x2e0 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:__rcu_read_unlock+0x51/0xd0 kernel/rcu/tree_plugin.h:421
Code: ec 03 43 0f b6 04 3c 84 c0 75 48 ff 0b 75 1d 4c 8d b7 40 04 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 75 5f 41 83 3e 00 <75> 20 43 0f b6 04 3c 84 c0 75 3a 8b 03 3d 00 00 00 40 73 0a 5b 41
RSP: 0018:ffffc90000007be8 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffff88807776a1fc RCX: ffff888077769dc0
RDX: 0000000000000100 RSI: ffffffff8a79fde0 RDI: ffff888077769dc0
RBP: 0000000000000002 R08: ffffffff8d89f02f R09: 1ffffffff1b13e05
R10: dffffc0000000000 R11: fffffbfff1b13e06 R12: 1ffff1100eeed43f
R13: 0000000000019000 R14: ffff88807776a200 R15: dffffc0000000000
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831
 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4f2/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 5f 39 8c f7 65 8b 05 f0 36 3c 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000322f720 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 73a29f1200653000
RDX: dffffc0000000000 RSI: ffffffff8a2b2800 RDI: 0000000000000001
RBP: ffffc9000322f7b0 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: dffffc0000000000
R13: 0000000000000001 R14: ffff88802c740550 R15: 1ffff92000645ee4
 spin_unlock_irqrestore include/linux/spinlock.h:419 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up+0x11c/0x180 kernel/sched/wait.c:157
 netlink_rcv_wake net/netlink/af_netlink.c:369 [inline]
 netlink_recvmsg+0xac6/0xe20 net/netlink/af_netlink.c:2010
 ____sys_recvmsg+0x2cd/0x5e0 net/socket.c:-1
 ___sys_recvmsg+0x21a/0x5c0 net/socket.c:2706
 __sys_recvmsg net/socket.c:2736 [inline]
 __do_sys_recvmsg net/socket.c:2746 [inline]
 __se_sys_recvmsg net/socket.c:2743 [inline]
 __x64_sys_recvmsg+0x1f9/0x2c0 net/socket.c:2743
 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: 0033:0x7f0c99404dd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0c9765e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007f0c9967dfa0 RCX: 00007f0c99404dd9
RDX: 0000000000000040 RSI: 0000200000000240 RDI: 0000000000000006
RBP: 00007f0c9949ad69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c9967e038 R14: 00007f0c9967dfa0 R15: 00007ffe08afb8c8
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/03 05:26 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_recvmsg
2026/01/29 18:47 linux-5.15.y 9eec9a14ee10 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_recvmsg
2025/12/17 16:28 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_recvmsg
2025/09/18 07:13 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_recvmsg
2025/08/10 06:15 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_recvmsg
* Struck through repros no longer work on HEAD.