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INFO: rcu detected stall in sock_alloc_file (2)

Status: upstream: reported on 2025/12/05 04:14
Reported-by: syzbot+0a5a607806b9dcb6d7c9@syzkaller.appspotmail.com
First crash: 15d, last: 15d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in sock_alloc_file 1 1 116d 116d 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 756d 756d 0/29 closed as invalid on 2024/02/01 10:31
linux-5.15 INFO: rcu detected stall in sock_alloc_file 1 1 167d 167d 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 335d 387d 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 2 20d 56d 0/3 upstream: reported on 2025/10/24 19:33
linux-6.1 INFO: rcu detected stall in sock_alloc_file 1 1 107d 107d 0/3 auto-obsoleted due to no activity on 2025/12/12 11:49

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10478 ticks this GP) idle=c26c/1/0x4000000000000000 softirq=38708/38919 fqs=193
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  2142184        698            0
rcu: 	cputime:    32370      19957           13   ==> 52360(ms)
rcu: 	(t=10503 jiffies g=47569 q=1648 ncpus=2)
CPU: 0 PID: 12140 Comm: syz.2.1766 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:unwind_next_frame+0xcd6/0x2970 arch/x86/kernel/unwind_orc.c:-1
Code: 84 c0 0f 85 07 1b 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 28 84 c0 48 8b 6c 24 10 48 8b 54 24 08 0f 85 08 1b 00 00 48 0f bf 03 <48> 01 c2 e9 1c 01 00 00 e8 9d e0 4a 00 e9 5e 0c 00 00 e8 93 e0 4a
RSP: 0018:ffffc90000006f30 EFLAGS: 00000246
RAX: 0000000000000068 RBX: ffffffff8ecd2830 RCX: ffff88807fc75a00
RDX: ffffc90000007000 RSI: ffffffff8cb9e760 RDI: 0000000000000005
RBP: ffffc900000070b8 R08: ffff88807fc75a00 R09: 0000000000000008
R10: 0000000000000009 R11: 0000000000000100 R12: ffffc90000007068
R13: dffffc0000000000 R14: ffffffff8ecd2831 R15: ffffffff8ecd2834
FS:  00007efef09cb6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f727dc00218 CR3: 000000005cb99000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 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+0x11e/0x2e0 mm/slub.c:3519
 skb_clone+0x1eb/0x370 net/core/skbuff.c:1915
 deliver_clone net/bridge/br_forward.c:125 [inline]
 maybe_deliver+0x98/0x150 net/bridge/br_forward.c:191
 br_flood+0x31b/0x680 net/bridge/br_forward.c:237
 br_handle_frame_finish+0x143d/0x1950 net/bridge/br_input.c:215
 nf_hook_bridge_pre net/bridge/br_input.c:299 [inline]
 br_handle_frame+0xb50/0x14c0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xf6b/0x3ac0 net/core/dev.c:5502
 __netif_receive_skb_one_core net/core/dev.c:5606 [inline]
 __netif_receive_skb+0x74/0x290 net/core/dev.c:5722
 process_backlog+0x380/0x6e0 net/core/dev.c:6050
 __napi_poll+0xc0/0x460 net/core/dev.c:6612
 napi_poll net/core/dev.c:6679 [inline]
 net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815
 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+0xc7/0x190 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:raw_spin_rq_unlock_irq+0x13/0x90 kernel/sched/sched.h:1385
Code: 0f 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 62 5c 11 09 66 90 41 57 41 56 53 66 90 e8 c4 06 1b 09 e8 4f 33 2e 00 fb 5b <41> 5e 41 5f c3 f3 0f 1e fa 49 be 00 00 00 00 00 fc ff df 49 89 ff
RSP: 0018:ffffc9000fe97588 EFLAGS: 00000282
RAX: 52eaced759168700 RBX: ffff8880b8e3cd48 RCX: 52eaced759168700
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80
RBP: ffffc9000fe97790 R08: ffffffff90da952f R09: 1ffffffff21b52a5
R10: dffffc0000000000 R11: fffffbfff21b52a6 R12: dffffc0000000000
R13: ffff8880b8e3c000 R14: ffff88807fc75a00 R15: ffff88807fc75a00
 __schedule+0x171e/0x44d0 kernel/sched/core.c:6703
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
 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+0xfa/0x110 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:1160 [inline]
 free_unref_page_prepare+0x1de/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 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+0x31d/0x410 mm/slub.c:3700
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 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+0x115/0x2e0 mm/slub.c:3526
 __d_alloc+0x31/0x730 fs/dcache.c:1773
 d_alloc_pseudo+0x1d/0x70 fs/dcache.c:1905
 alloc_file_pseudo+0xcc/0x200 fs/file_table.c:329
 sock_alloc_file+0xb7/0x280 net/socket.c:469
 __sys_socketpair+0x2d0/0x550 net/socket.c:1802
 __do_sys_socketpair net/socket.c:1831 [inline]
 __se_sys_socketpair net/socket.c:1828 [inline]
 __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1828
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7efeefb8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efef09cb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007efeefde5fa0 RCX: 00007efeefb8f749
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001
RBP: 00007efeefc13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 00002000000001c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efeefde6038 R14: 00007efeefde5fa0 R15: 00007ffcc11549b8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/05 04:13 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sock_alloc_file
* Struck through repros no longer work on HEAD.