INFO: rcu detected stall in sock_alloc_file (2)

Status: upstream: reported on 2026/04/01 17:08
Reported-by: syzbot+f74682e9cfcbf29e3c25@syzkaller.appspotmail.com
First crash: 194d, last: 1d22h
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in sock_alloc_file (2) 1 1 311d 311d 0/2 auto-obsoleted due to no activity on 2026/03/15 04:14
linux-6.6 INFO: rcu detected stall in sock_alloc_file 1 1 413d 413d 0/2 auto-obsoleted due to no activity on 2025/12/03 21:35
upstream INFO: rcu detected stall in sock_alloc_file fs 1 1 1053d 1053d 0/29 closed as invalid on 2024/02/01 10:31
upstream INFO: rcu detected stall in sock_alloc_file (3) mm 1 5 323d 459d 0/29 auto-obsoleted due to no activity on 2026/02/21 17:58
linux-5.15 INFO: rcu detected stall in sock_alloc_file 1 1 464d 464d 0/3 auto-obsoleted due to no activity on 2025/10/13 16:41
upstream INFO: rcu detected stall in sock_alloc_file (2) mm 1 6 632d 684d 0/29 auto-obsoleted due to no activity on 2025/04/19 00:40
linux-5.15 INFO: rcu detected stall in sock_alloc_file (2) 1 9 5d00h 353d 0/3 upstream: reported on 2025/10/24 19:33
linux-6.1 INFO: rcu detected stall in sock_alloc_file 1 1 404d 404d 0/3 auto-obsoleted due to no activity on 2025/12/12 11:49
upstream BUG: soft lockup in sock_alloc_file prio:low mm 1 11 8d11h 201d 0/29 closed as invalid on 2026/10/06 01:52

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2646 jiffies s: 164885 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 31601 Comm: syz.5.6281 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:asm_sysvec_irq_work+0x0/0x20 arch/x86/include/asm/idtentry.h:722
Code: e9 b5 03 00 00 90 90 90 90 90 0f 01 ca fc 6a ff e8 b5 02 00 00 48 89 c4 48 89 e7 e8 9a a4 f3 ff e9 95 03 00 00 90 90 90 90 90 <0f> 01 ca fc 6a ff e8 95 02 00 00 48 89 c4 48 89 e7 e8 6a a9 f3 ff
RSP: 0018:ffffc90000007ab8 EFLAGS: 00000006
RAX: a967f17f340bdb00 RBX: 1ffff92000000f64 RCX: a967f17f340bdb00
RDX: dffffc0000000000 RSI: ffffffff8a8c19a0 RDI: ffffffff8adf71a0
RBP: ffffc90000007bd0 R08: ffff8880b8c357cb R09: 1ffff11017186af9
R10: dffffc0000000000 R11: ffffed1017186afa R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8c3bb00 R15: 0000000000000001
FS:  00007f83c33f66c0(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005572311c44b0 CR3: 0000000062f8d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 d2 68 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc90000007ae0 EFLAGS: 00000206
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x156/0x170 net/mac80211/util.c:826
 mac80211_hwsim_beacon+0xb7/0x1b0 drivers/net/wireless/mac80211_hwsim.c:2153
 __run_hrtimer kernel/time/hrtimer.c:1751 [inline]
 __hrtimer_run_queues+0x522/0xc90 kernel/time/hrtimer.c:1815
 hrtimer_run_softirq+0x173/0x290 kernel/time/hrtimer.c:1832
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:mod_node_state+0x72/0x140 mm/vmstat.c:645
Code: 41 f7 c4 ff 0f 00 00 0f 85 a3 00 00 00 41 c1 fc 0c 49 63 f4 eb 11 89 c8 65 44 0f b0 64 1a 01 38 c8 0f 84 80 00 00 00 65 8a 02 <48> 0f be f8 65 8a 4c 1a 01 4c 0f be e1 49 01 f4 4d 89 e0 49 f7 d8
RSP: 0018:ffffc9000c5efa50 EFLAGS: 00000282
RAX: 0000000000000018 RBX: 0000000000000006 RCX: dffffc0000000000
RDX: 00000000000411a0 RSI: fffffffffffffff8 RDI: ffff88813fffa000
RBP: 0000000000000000 R08: ffff8880b8c357cb R09: 1ffff11017186af9
R10: dffffc0000000000 R11: ffffed1017186afa R12: 00000000fffffff8
R13: ffff8880184409c0 R14: ffff88813fffa000 R15: 0000000000000006
 unaccount_slab mm/slab.h:647 [inline]
 __free_slab+0x117/0x350 mm/slub.c:2020
 free_slab mm/slub.c:2036 [inline]
 discard_slab mm/slub.c:2042 [inline]
 __unfreeze_partials+0x188/0x1e0 mm/slub.c:2591
 put_cpu_partial+0x17c/0x250 mm/slub.c:2667
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737
 slab_alloc_node mm/slub.c:3359 [inline]
 slab_alloc mm/slub.c:3367 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3374 [inline]
 kmem_cache_alloc+0x18b/0x2f0 mm/slub.c:3383
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 __alloc_file+0x25/0x230 fs/file_table.c:138
 alloc_empty_file+0x90/0x180 fs/file_table.c:187
 alloc_file+0x5b/0x5f0 fs/file_table.c:229
 alloc_file_pseudo+0x180/0x200 fs/file_table.c:272
 sock_alloc_file+0xb3/0x240 net/socket.c:467
 __sys_socketpair+0x372/0x540 net/socket.c:1764
 __do_sys_socketpair net/socket.c:1786 [inline]
 __se_sys_socketpair net/socket.c:1783 [inline]
 __x64_sys_socketpair+0x97/0xb0 net/socket.c:1783
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f83c519e1d9
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:00007f83c33f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007f83c5425fa0 RCX: 00007f83c519e1d9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001
RBP: 00007f83c5235888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000740 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f83c5426038 R14: 00007f83c5425fa0 R15: 00007ffd8fe8d9e8
 </TASK>

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/11 02:32 linux-6.1.y a500ba24937a 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/09/20 06:07 linux-6.1.y 1a8763b93150 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/09/10 21:14 linux-6.1.y cf82dcca9634 1fe56c0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/07/26 12:24 linux-6.1.y dc5c83b7f5f8 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/07/25 20:01 linux-6.1.y dc5c83b7f5f8 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/07/22 08:02 linux-6.1.y 090666d3cc90 b561ce9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/07/13 00:44 linux-6.1.y 090666d3cc90 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/07/08 17:20 linux-6.1.y 090666d3cc90 88a4b44c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/07/01 20:37 linux-6.1.y fdb6fcb41cc7 27192279 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/06/27 09:02 linux-6.1.y fdb6fcb41cc7 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/06/23 05:24 linux-6.1.y fdb6fcb41cc7 5a630be6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/06/18 23:45 linux-6.1.y 228da13e907e a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/04/01 17:08 linux-6.1.y 1989cd3d56e2 9a1f7828 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sock_alloc_file
* Struck through repros no longer work on HEAD.