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: 140d, last: 24d
▶ ▼ Similar bugs (8)
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 258d 258d 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 359d 359d 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 999d 999d 0/29 closed as invalid on 2024/02/01 10:31
upstream INFO: rcu detected stall in sock_alloc_file (3) mm 1 5 269d 405d 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 410d 410d 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 578d 630d 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 8 30d 299d 0/3 upstream: reported on 2025/10/24 19:33
linux-6.1 INFO: rcu detected stall in sock_alloc_file 1 1 350d 350d 0/3 auto-obsoleted due to no activity on 2025/12/12 11:49

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2686 jiffies s: 30301 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8045 Comm: syz.3.1487 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:migrate_enable+0x99/0x220 kernel/sched/core.c:2248
Code: 66 45 85 ff 0f 84 f9 00 00 00 4d 89 f7 bf 01 00 00 00 e8 ca c9 ff ff 49 8d be 18 04 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 05 e8 20 6e 7a 00 49 81 c6 28 04 00 00 4d 39 b7 18 04 00 00 74
RSP: 0018:ffffc900001e0770 EFLAGS: 00000046
RAX: 1ffff1100fad4083 RBX: ffff88807d6a0438 RCX: ffffffff96c16103
RDX: 0000000000000100 RSI: ffffc9001a944048 RDI: ffff88807d6a0418
RBP: 1ffff1100fad4087 R08: dffffc0000000000 R09: 1ffffffff2161e48
R10: dffffc0000000000 R11: fffffbfff2161e49 R12: 0000000000120000
R13: dffffc0000000000 R14: ffff88807d6a0000 R15: ffff88807d6a0000
FS:  00007f62ee03d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000009000 CR3: 000000002804d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 bpf_prog_run_array include/linux/bpf.h:1672 [inline]
 trace_call_bpf+0x4b1/0x6b0 kernel/trace/bpf_trace.c:135
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027
 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
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 a2 7c 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:ffffc900001e0ae0 EFLAGS: 00000206
RAX: 2a822f72f7790c00 RBX: 1ffff9200003c164 RCX: 2a822f72f7790c00
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf5de0
RBP: ffffc900001e0bd0 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002
 __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:2147
 __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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 3f 89 1e f7 65 8b 05 b0 3a c8 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9001a7d7940 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 2a822f72f7790c00
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 0000000000000001
RBP: ffffc9001a7d79d8 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: dffffc0000000000
R13: ffff88804e0f0000 R14: ffffffff96ed1410 R15: 1ffff920034faf28
 __debug_check_no_obj_freed lib/debugobjects.c:1054 [inline]
 debug_check_no_obj_freed+0x471/0x520 lib/debugobjects.c:1075
 free_pages_prepare mm/page_alloc.c:1493 [inline]
 free_pcp_prepare mm/page_alloc.c:1537 [inline]
 free_unref_page_prepare+0x2c3/0x9e0 mm/page_alloc.c:3414
 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509
 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_lru+0x182/0x2e0 mm/slub.c:3390
 __d_alloc+0x2e/0x6e0 fs/dcache.c:1774
 d_alloc_pseudo+0x19/0x70 fs/dcache.c:1906
 alloc_file_pseudo+0xe0/0x200 fs/file_table.c:265
 sock_alloc_file+0xb3/0x240 net/socket.c:467
 __sys_socketpair+0x2cc/0x540 net/socket.c:1757
 __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: 0033:0x7f62ed19de99
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:00007f62ee03d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007f62ed425fa0 RCX: 00007f62ed19de99
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 00007f62ed233eaf R08: 0000000000000000 R09: 0000000000000000
R10: 00002000000001c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f62ed426038 R14: 00007f62ed425fa0 R15: 00007fff9e429a08
 </TASK>

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.