syzbot


INFO: rcu detected stall in sys_socket

Status: upstream: reported on 2025/07/12 12:18
Reported-by: syzbot+3a18ae63a3331d652199@syzkaller.appspotmail.com
First crash: 262d, last: 4d10h
Similar bugs (16)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_socket (4) fs 1 1 1798d 1798d 0/29 auto-closed as invalid on 2021/07/27 17:27
linux-5.15 INFO: rcu detected stall in sys_socket 1 1 910d 910d 0/3 auto-obsoleted due to no activity on 2024/01/11 06:48
upstream INFO: rcu detected stall in sys_socket (5) net 1 2 1636d 1661d 0/29 auto-closed as invalid on 2022/01/06 01:08
upstream INFO: rcu detected stall in sys_socket mm 1 11 2309d 2310d 0/29 closed as invalid on 2019/12/04 14:04
linux-4.19 INFO: rcu detected stall in sys_socket 1 1 1439d 1439d 0/1 auto-closed as invalid on 2022/08/20 07:08
upstream INFO: rcu detected stall in sys_socket (10) mm 1 C done 214 2d08h 852d 0/29 upstream: reported C repro on 2023/11/30 15:24
linux-6.1 INFO: rcu detected stall in sys_socket 1 2 604d 604d 0/3 auto-obsoleted due to no activity on 2024/11/13 04:32
linux-6.1 INFO: rcu detected stall in sys_socket (3) origin:lts-only 1 C inconclusive 34 3d19h 204d 0/3 upstream: reported C repro on 2025/09/09 01:58
upstream INFO: rcu detected stall in sys_socket (6) cgroups mm 1 2 1295d 1339d 0/29 auto-obsoleted due to no activity on 2022/12/12 22:48
upstream INFO: rcu detected stall in sys_socket (7) kernel 1 2 1154d 1187d 0/29 auto-obsoleted due to no activity on 2023/05/02 14:50
linux-6.1 INFO: rcu detected stall in sys_socket (2) 1 3 393d 447d 0/3 auto-obsoleted due to no activity on 2025/06/11 16:02
upstream INFO: rcu detected stall in sys_socket (9) mm kasan 1 2 972d 981d 0/29 closed as invalid on 2023/09/07 14:25
upstream INFO: rcu detected stall in sys_socket (2) mm 1 3 2275d 2275d 0/29 closed as invalid on 2020/01/08 05:23
linux-5.15 INFO: rcu detected stall in sys_socket (2) origin:upstream 1 C error 51 6d06h 759d 0/3 upstream: reported C repro on 2024/03/02 17:55
upstream INFO: rcu detected stall in sys_socket (3) mm 1 4 2274d 2275d 0/29 closed as invalid on 2020/01/09 08:13
android-5-15 BUG: soft lockup in sys_socket 1 C error 26 571d 720d 0/2 auto-obsoleted due to no activity on 2024/11/29 22:24

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (5283 ticks this GP) idle=4264/1/0x4000000000000000 softirq=27698/27698 fqs=2799
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1571448          1            0
rcu: 	cputime:    14341      38158           35   ==> 52520(ms)
rcu: 	(t=10503 jiffies g=35677 q=1957 ncpus=2)
CPU: 0 PID: 9712 Comm: syz.3.1437 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__stack_depot_save+0x0/0x630 lib/stackdepot.c:361
Code: fb 40 73 10 b8 01 00 00 00 89 d9 48 d3 e0 48 83 c4 08 5b c3 be 01 00 00 00 48 c7 c7 80 eb 7e 8d 48 89 da e8 42 64 00 00 eb da <f3> 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 20 41 89 cf 89
RSP: 0018:ffffc900000073d8 EFLAGS: 00000246
RAX: 0000000000000029 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000029 RDI: ffffc900000073e0
RBP: ffffc90000007608 R08: ffffffff8e8b02af R09: 1ffffffff1d16055
R10: dffffc0000000000 R11: fffffbfff1d16056 R12: 0000000000000000
R13: ffffc900000076b8 R14: ffff88802b2fab48 R15: ffffc900000073e0
FS:  00007f03837816c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000001d379000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_set_track+0x5f/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 kmem_cache_free+0xf8/0x270 mm/slub.c:3852
 kfree_skb include/linux/skbuff.h:1264 [inline]
 neigh_connected_output+0x3e1/0x450 net/core/neighbour.c:1600
 neigh_output include/net/neighbour.h:543 [inline]
 ip6_finish_output2+0xe3d/0x1630 net/ipv6/ip6_output.c:141
 dst_output include/net/dst.h:467 [inline]
 NF_HOOK include/linux/netfilter.h:304 [inline]
 ndisc_send_skb+0xc26/0x14f0 net/ipv6/ndisc.c:513
 addrconf_rs_timer+0x2d5/0x630 net/ipv6/addrconf.c:4024
 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x542/0x800 kernel/time/timer.c:2023
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5255
Code: 0f 84 33 01 00 00 48 85 db 0f 85 52 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 90 43 32 09 e8 eb 27 30 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900198e7638 EFLAGS: 00000282
RAX: 82262e562ee63600 RBX: 0000000000000000 RCX: 82262e562ee63600
RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c89a0
RBP: ffffc900198e7690 R08: ffffffff911c352f R09: 1ffffffff22386a5
R10: dffffc0000000000 R11: fffffbfff22386a6 R12: ffff888023ce9e00
R13: dffffc0000000000 R14: ffff888069f81e00 R15: ffff8880b8e3cac8
 context_switch kernel/sched/core.c:5384 [inline]
 __schedule+0x155b/0x45a0 kernel/sched/core.c:6700
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x111/0x120 kernel/locking/spinlock.c:194
 __debug_check_no_obj_freed lib/debugobjects.c:999 [inline]
 debug_check_no_obj_freed+0x51f/0x540 lib/debugobjects.c:1020
 free_pages_prepare mm/page_alloc.c:1187 [inline]
 free_unref_page_prepare+0x1da/0x8c0 mm/page_alloc.c:2365
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458
 discard_slab mm/slub.c:2127 [inline]
 __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667
 put_cpu_partial+0x17c/0x250 mm/slub.c:2743
 __slab_free+0x319/0x400 mm/slub.c:3700
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc_lru+0x111/0x2d0 mm/slub.c:3526
 alloc_inode_sb include/linux/fs.h:2946 [inline]
 sock_alloc_inode+0x28/0xc0 net/socket.c:308
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x63/0x1d0 fs/inode.c:1049
 sock_alloc net/socket.c:634 [inline]
 __sock_create+0x12d/0x940 net/socket.c:1534
 sock_create net/socket.c:1626 [inline]
 __sys_socket_create net/socket.c:1663 [inline]
 __sys_socket+0xd7/0x1a0 net/socket.c:1714
 __do_sys_socket net/socket.c:1728 [inline]
 __se_sys_socket net/socket.c:1726 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1726
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f038299c799
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:00007f0383781028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007f0382c15fa0 RCX: 00007f038299c799
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000011
RBP: 00007f0382a32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0382c16038 R14: 00007f0382c15fa0 R15: 00007fff96429698
 </TASK>

Crashes (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/27 20:24 linux-6.6.y c09fbcd31ae6 74a13a23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2026/03/07 22:54 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_socket
2026/01/29 06:54 linux-6.6.y cbb31f77b879 0adc945e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2026/01/07 12:09 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_socket
2025/12/20 01:03 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2025/12/11 06:11 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2025/11/27 11:58 linux-6.6.y 1e89a1be4fe9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2025/11/19 02:31 linux-6.6.y 0a805b6ea8cd ef766cd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2025/10/27 01:47 linux-6.6.y 4a243110dc88 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2025/10/03 21:37 linux-6.6.y f34f16e5c632 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_socket
2025/08/28 14:20 linux-6.6.y bb9c90ab9c5a e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2025/08/28 11:58 linux-6.6.y bb9c90ab9c5a e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2025/08/25 14:44 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2025/08/06 11:41 linux-6.6.y 3a8ababb8b6a ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_socket
2025/07/12 12:18 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_socket
* Struck through repros no longer work on HEAD.