syzbot
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
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>
* Struck through repros no longer work on HEAD.