syzbot
INFO: rcu detected stall in sock_alloc_file (2)
Status:
upstream: reported on 2025/10/24 19:33
Reported-by: syzbot+adbc0bd310742910f945@syzkaller.appspotmail.com
First crash: 350d, last: 2d01h
Sample crash report:
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-....: (14 ticks this GP) idle=8fd/1/0x4000000000000002 softirq=59642/59642 fqs=2589
(detected by 0, t=10502 jiffies, g=81509, q=24229)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 27010 Comm: syz.3.3817 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x80 kernel/kcov.c:293
Code: 28 4d 39 ca 77 22 89 ff 89 f6 4a c7 44 02 08 03 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 <48> 8b 04 24 65 48 8b 0d f4 48 89 7e 65 8b 15 f5 48 89 7e 81 e2 00
RSP: 0018:ffffc90000dd0570 EFLAGS: 00000086
RAX: 0000000000000001 RBX: ffff8880b913b1f0 RCX: 97e8232133253300
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000008
RBP: 0000000000000001 R08: ffff8880b913b1fb R09: 1ffff1101722763f
R10: dffffc0000000000 R11: ffffed1017227640 R12: 0000000000000023
R13: dffffc0000000001 R14: ffff8880b913b1f8 R15: dffffc0000000000
FS: 00007f31139cc6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000029c0 CR3: 00000000227b3000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
__irq_work_queue_local+0x62/0x190 kernel/irq_work.c:-1
irq_work_queue_on+0x11e/0x220 kernel/irq_work.c:109
rcu_read_unlock_special+0x377/0x4a0 kernel/rcu/tree_plugin.h:667
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
BPF_PROG_RUN_ARRAY include/linux/bpf.h:1446 [inline]
trace_call_bpf+0x4f9/0x5b0 kernel/trace/bpf_trace.c:127
perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10026
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_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
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 82 fc 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc90000dd0a20 EFLAGS: 00000206
RAX: 97e8232133253300 RBX: 1ffff920001ba148 RCX: 97e8232133253300
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4b80
RBP: ffffc90000dd0b00 R08: ffffffff902140d7 R09: 1ffffffff204281a
R10: dffffc0000000000 R11: fffffbfff204281b R12: ffffffff8c323400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
process_backlog+0x3e5/0x770 net/core/dev.c:6543
__napi_poll+0xbb/0x430 net/core/dev.c:7101
napi_poll net/core/dev.c:7168 [inline]
net_rx_action+0x522/0xa80 net/core/dev.c:7258
handle_softirqs+0x336/0x830 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:finish_lock_switch+0x12f/0x290 kernel/sched/core.c:4804
Code: 83 c7 18 be ff ff ff ff e8 be bc 6d 08 85 c0 74 46 4d 85 ff 75 62 0f 1f 44 00 00 48 89 df e8 18 2d 77 08 e8 a3 f2 2a 00 fb 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 2f 0e fe ff 43 80 3c 2c
RSP: 0018:ffffc900033ef798 EFLAGS: 00000286
RAX: 97e8232133253300 RBX: ffff888026c65940 RCX: 97e8232133253300
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4b80
RBP: 1ffff11017227613 R08: ffffffff902140d7 R09: 1ffffffff204281a
R10: dffffc0000000000 R11: fffffbfff204281b R12: 1ffff110172275c1
R13: dffffc0000000000 R14: ffff8880b913ae08 R15: 0000000000000000
finish_task_switch+0x12f/0x650 kernel/sched/core.c:4921
context_switch kernel/sched/core.c:5052 [inline]
__schedule+0x11cb/0x4350 kernel/sched/core.c:6395
preempt_schedule_notrace+0xd9/0x120 kernel/sched/core.c:6650
preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124
trace_lock_release include/trace/events/lock.h:58 [inline]
lock_release+0xb5/0x8a0 kernel/locking/lockdep.c:5748
might_alloc include/linux/sched/mm.h:207 [inline]
slab_pre_alloc_hook+0x27/0xc0 mm/slab.h:492
slab_alloc_node mm/slub.c:3139 [inline]
slab_alloc mm/slub.c:3233 [inline]
kmem_cache_alloc+0x3d/0x280 mm/slub.c:3238
kmem_cache_zalloc include/linux/slab.h:728 [inline]
__alloc_file+0x25/0x240 fs/file_table.c:132
alloc_empty_file+0x90/0x180 fs/file_table.c:181
alloc_file+0x5c/0x510 fs/file_table.c:223
alloc_file_pseudo+0x180/0x200 fs/file_table.c:263
sock_alloc_file+0xb3/0x240 net/socket.c:464
__sys_socketpair+0x372/0x540 net/socket.c:1683
__do_sys_socketpair net/socket.c:1705 [inline]
__se_sys_socketpair net/socket.c:1702 [inline]
__x64_sys_socketpair+0x97/0xb0 net/socket.c:1702
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: 0033:0x7f3115774199
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:00007f31139cc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007f31159fbfa0 RCX: 00007f3115774199
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001
RBP: 00007f311580b8e0 R08: 0000000000000000 R09: 0000000000000000
R10: 00002000000029c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f31159fc038 R14: 00007f31159fbfa0 R15: 00007ffc124d1358
</TASK>
net_ratelimit: 6690 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
net_ratelimit: 6375 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
Struck through repros no longer work on HEAD.