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INFO: rcu detected stall in file_free (2)

Status: auto-obsoleted due to no activity on 2026/05/19 15:58
Subsystems: fs
[Documentation on labels]
First crash: 121d, last: 121d
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
a5d25b3d-39f0-4fbb-8c74-aba05274225f assessment-security 💥 INFO: rcu detected stall in file_free (2) 2026/05/15 10:51 2026/05/15 10:51 2026/05/15 10:52 9cd3beaadf14b3a22d15fd97a0bf081ee41ebe01
failed to run ["git" "pull" "origin" "HEAD" "--depth=1" "--allow-unrelated-histories"]: exit status 1
fatal: write error: No space left on device
fatal: fetch-pack: invalid index-pack output
91b8eeb1-f6d3-4957-accc-67d1ef53bfe8 repro INFO: rcu detected stall in file_free (2) 2026/03/07 13:28 2026/03/07 13:28 2026/03/07 13:46 31e9c887f7dc24e04b3ca70d0d54fc34141844b0

			
		
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in file_free fs 1 5 607d 698d 0/29 auto-obsoleted due to no activity on 2025/01/18 07:51
upstream BUG: soft lockup in file_free fs 1 1 7d11h 3d11h 0/29 moderation: reported on 2026/06/16 10:58

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: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P28884/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=113285, q=2682 ncpus=2)
task:syz.0.6595      state:R  running task     stack:27512 pid:28884 tgid:28883 ppid:27260  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x1568/0x5290 kernel/sched/core.c:6907
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234
 irqentry_exit+0x599/0x620 kernel/entry/common.c:239
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2d7/0x3a0 kernel/locking/lockdep.c:5893
Code: d7 76 11 00 00 00 00 eb b5 e8 25 c4 fd 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 a5 91 76 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 8a a8 00 0a cc 48 8d 3d c2 52 73
RSP: 0018:ffffc9000d9ff2e0 EFLAGS: 00000282
RAX: f583d50cc24eff00 RBX: 0000000000000202 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8e151aa7 RDI: ffffffff8c276500
RBP: ffff888031292948 R08: ffffc9000d9ffbb0 R09: 0000000000000000
R10: ffffc9000d9ff438 R11: fffff52001b3fe89 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8e75e0a0 R15: ffff888031291e40
 rcu_lock_release include/linux/rcupdate.h:322 [inline]
 rcu_read_unlock include/linux/rcupdate.h:881 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2670 [inline]
 slab_free mm/slub.c:6082 [inline]
 kmem_cache_free+0x180/0x610 mm/slub.c:6212
 file_free+0x24/0x1e0 fs/file_table.c:71
 __fput_deferred+0x2a3/0x380 fs/file_table.c:524
 fput_close+0x11f/0x240 fs/file_table.c:586
 path_openat+0x311d/0x3860 fs/namei.c:4839
 do_file_open+0x23e/0x4a0 fs/namei.c:4859
 do_sys_openat2+0x113/0x200 fs/open.c:1366
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_openat fs/open.c:1388 [inline]
 __se_sys_openat fs/open.c:1383 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1383
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa15219c629
RSP: 002b:00007fa152fa4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa152415fa0 RCX: 00007fa15219c629
RDX: 0000000000000002 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007fa152232b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa152416038 R14: 00007fa152415fa0 R15: 00007ffdb91a2cc8
 </TASK>
rcu: rcu_preempt kthread starved for 2555 jiffies! g113285 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27624 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x1568/0x5290 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7004
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 20859 Comm: kworker/u8:38 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker
RIP: 0010:pie_calculate_probability+0x123/0x7e0 net/sched/sch_pie.c:331
Code: 8b 5c 24 28 49 8b 04 24 48 89 44 24 28 eb 07 e8 a3 67 1c f8 31 db 4c 89 64 24 38 31 ff 48 89 de e8 72 6c 1c f8 48 89 5c 24 18 <48> 85 db 0f 95 44 24 06 31 ff 89 ee e8 bc 6b 1c f8 89 6c 24 44 85
RSP: 0018:ffffc90000007ba8 EFLAGS: 00000246
RAX: ffffffff89a7d33e RBX: 0000000000000000 RCX: ffff88807ef43c80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f78 R12: ffffc90015252a18
R13: ffffc90015252a10 R14: dffffc0000000000 R15: ffff88806e13fada
FS:  0000000000000000(0000) GS:ffff8881254ae000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa315731478 CR3: 000000000e54a000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 fq_pie_timer+0x288/0x5b0 net/sched/sch_fq_pie.c:402
 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 blake2s_compress+0xf9/0x1eb0 lib/crypto/x86/blake2s.h:42
 blake2s_update+0x14b/0x450 lib/crypto/blake2s.c:119
 hmac+0x1fc/0x3b0 drivers/net/wireguard/noise.c:324
 kdf+0x1a3/0x2b0 drivers/net/wireguard/noise.c:375
 mix_precomputed_dh drivers/net/wireguard/noise.c:426 [inline]
 wg_noise_handshake_create_initiation+0x473/0x830 drivers/net/wireguard/noise.c:560
 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline]
 wg_packet_handshake_send_worker+0x18d/0x350 drivers/net/wireguard/send.c:51
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
net_ratelimit: 8746 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 veth0_to_bridge with own address as source address (addr:b2:ab:78:6f:0a:5b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:b2:ab:78:6f:0a:5b, 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:b2:ab:78:6f:0a:5b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
net_ratelimit: 11335 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:b2:ab:78:6f:0a:5b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, 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:1b, 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)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/18 15:58 net ccd8e87748ad 77d4d919 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in file_free
* Struck through repros no longer work on HEAD.