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: 178d, last: 8d11h
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 137d 137d 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 238d 238d 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 878d 878d 0/29 closed as invalid on 2024/02/01 10:31
upstream INFO: rcu detected stall in sock_alloc_file (3) mm 1 5 148d 284d 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 289d 289d 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 457d 509d 0/29 auto-obsoleted due to no activity on 2025/04/19 00:40
linux-6.1 INFO: rcu detected stall in sock_alloc_file (2) 1 1 19d 19d 0/3 upstream: reported on 2026/04/01 17:08
linux-6.1 INFO: rcu detected stall in sock_alloc_file 1 1 229d 229d 0/3 auto-obsoleted due to no activity on 2025/12/12 11:49

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (4 ticks this GP) idle=00f/1/0x4000000000000002 softirq=13786/13791 fqs=2066 
	(detected by 1, t=10506 jiffies, g=18373, q=1003)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6589 Comm: syz.2.615 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:llist_add_batch+0x1/0xa0 lib/llist.c:28
Code: e5 f8 4c 89 33 4d 89 ee eb 05 e8 ca 36 96 fd 4c 89 f0 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 b3 36 96 fd eb e7 00 55 <41> 57 41 56 41 55 41 54 53 48 89 d3 49 89 f6 49 89 ff e8 98 36 96
RSP: 0018:ffffc90000007648 EFLAGS: 00000082
RAX: 1ffffffff17c6304 RBX: ffff8880b903b1f0 RCX: ffff8880239cd940
RDX: ffff8880b9033d70 RSI: ffff8880b903b1f0 RDI: ffff8880b903b1f0
RBP: 0000000000000000 R08: ffff8880b903b1fb R09: 1ffff1101720763f
R10: dffffc0000000000 R11: ffffed1017207640 R12: 0000000000000000
R13: dffffc0000000001 R14: ffffffff8be31820 R15: dffffc0000000000
FS:  00007f510e9d86c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003ff6 CR3: 0000000072d4f000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 llist_add include/linux/llist.h:219 [inline]
 __irq_work_queue_local+0xad/0x190 kernel/irq_work.c:61
 irq_work_queue_on+0x11e/0x220 kernel/irq_work.c:109
 rcu_read_unlock_special+0x37b/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:1444 [inline]
 trace_call_bpf+0x4f9/0x5b0 kernel/trace/bpf_trace.c:127
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016
 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 12 f2 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:ffffc90000007b00 EFLAGS: 00000206
RAX: 117ed87ec4f27a00 RBX: 1ffff92000000f64 RCX: 117ed87ec4f27a00
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f980
RBP: ffffc90000007bd8 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: ffffffff8c322f00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831
 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4f2/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x339/0x830 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:__phys_addr+0x0/0x170 arch/x86/mm/physaddr.c:16
Code: 48 89 df e8 a2 25 00 00 4c 89 ff 31 f6 e8 e8 b4 7e 00 b8 01 00 00 00 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 00 00 cc cc <41> 57 41 56 53 48 89 fb e8 63 25 43 00 48 bf ff ff ff 7f ff ff ff
RSP: 0018:ffffc90002ddf910 EFLAGS: 00000286
RAX: ffffea0001f92400 RBX: ffff88807e491100 RCX: ffffea0000000000
RDX: 0000000000000001 RSI: ffffc90002ddf978 RDI: ffff88807e491100
RBP: 0000000000000000 R08: ffff8880239fe310 R09: 000000008024001c
R10: dffffc0000000000 R11: ffffed1017207662 R12: ffffc90002ddf978
R13: 0000000000000001 R14: ffffffff81be3b77 R15: ffff888016de9500
 virt_to_head_page include/linux/mm.h:911 [inline]
 memcg_slab_free_hook+0x89/0x1f0 mm/slab.h:348
 do_slab_free mm/slub.c:3437 [inline]
 ___cache_free+0x63/0x120 mm/slub.c:3511
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 __d_alloc+0x2a/0x6f0 fs/dcache.c:1749
 d_alloc_pseudo+0x19/0x70 fs/dcache.c:1880
 alloc_file_pseudo+0xe0/0x200 fs/file_table.c:256
 sock_alloc_file+0xb3/0x240 net/socket.c:464
 __sys_socketpair+0x372/0x540 net/socket.c:1682
 __do_sys_socketpair net/socket.c:1704 [inline]
 __se_sys_socketpair net/socket.c:1701 [inline]
 __x64_sys_socketpair+0x97/0xb0 net/socket.c:1701
 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: 0033:0x7f511077e819
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:00007f510e9d8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007f51109f7fa0 RCX: 00007f511077e819
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 00007f5110814c91 R08: 0000000000000000 R09: 0000000000000000
R10: 00002000000001c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f51109f8038 R14: 00007f51109f7fa0 R15: 00007ffcf80ac198
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/12 22:41 linux-5.15.y 91d48252ad4b 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sock_alloc_file
2026/02/27 23:35 linux-5.15.y 3330a8d33e08 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sock_alloc_file
2025/12/24 03:15 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sock_alloc_file
2025/11/30 01:31 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sock_alloc_file
2025/10/24 19:33 linux-5.15.y ac56c046adf4 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sock_alloc_file
* Struck through repros no longer work on HEAD.