syzbot


INFO: rcu detected stall in exit_to_user_mode_loop

Status: upstream: reported on 2025/06/21 15:44
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+2642f347f7309b4880dc@syzkaller.appspotmail.com
First crash: 34d, last: 2d03h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mm?] INFO: rcu detected stall in exit_to_user_mode_loop 0 (1) 2025/06/21 15:44

Sample crash report:
bridge0: received packet on veth0_to_bridge with own address as source address (addr:ae:ba:96:e0:27:03, vlan:0)
bridge0: received packet on bridge_slave_0 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): P24314/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=179737, q=3109 ncpus=2)
task:syz.5.4666      state:R  running task     stack:22024 pid:24314 tgid:24311 ppid:22210  task_flags:0x400548 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x51/0x190 kernel/locking/lockdep.c:5936
Code: 3a 3a 04 00 0f 84 fe 00 00 00 65 8b 05 48 44 36 07 85 c0 0f 85 ef 00 00 00 65 4c 8b 2c 25 08 00 9d 92 41 83 bd ec 0a 00 00 00 <0f> 85 d8 00 00 00 89 f5 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f 04
RSP: 0018:ffffc9000bca7768 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ba3af726991a6100
RDX: ffff888021f8bc00 RSI: 00000000ffffffff RDI: ffffffff8e13ee20
RBP: 0000000000000000 R08: ffff888021f8bc00 R09: 0000000000000002
R10: 0000000000000003 R11: 0000000000000000 R12: ffffc9000bca7828
R13: ffff888021f8bc00 R14: 0000000000000000 R15: 1ffff92001794f08
 xa_entry include/linux/xarray.h:1226 [inline]
 xas_find+0x489/0x990 lib/xarray.c:1423
 xa_find+0x18c/0x2b0 lib/xarray.c:2197
 io_uring_clean_tctx+0xb9/0x1a0 io_uring/tctx.c:194
 io_uring_cancel_generic+0x6ca/0x7d0 io_uring/io_uring.c:3213
 io_uring_files_cancel include/linux/io_uring.h:19 [inline]
 do_exit+0x345/0x22e0 kernel/exit.c:911
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe0af38e929
RSP: 002b:00007fe0b018b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fe0af5b5fa8 RCX: 00007fe0af38e929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe0af5b5fa8
RBP: 00007fe0af5b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0af5b5fac
R13: 0000000000000000 R14: 00007fe0af6df940 R15: 00007fe0af6dfa28
 </TASK>
net_ratelimit: 11431 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, 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:ae:ba:96:e0:27:03, 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 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:ae:ba:96:e0:27:03, 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)
net_ratelimit: 10393 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:ae:ba:96:e0:27:03, 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 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:ae:ba:96:e0:27:03, 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 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:ae:ba:96:e0:27:03, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (41):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/01 11:17 upstream 66701750d556 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/30 05:50 upstream d0b3b7b22dfa fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/29 03:16 upstream aaf724ed6926 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/28 13:50 upstream aaf724ed6926 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/28 07:06 upstream 35e261cd95dd fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/26 01:36 upstream 92ca6c498a5e 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/24 00:18 upstream 78f4e737a53e 1a7fb460 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/18 11:15 upstream 52da431bf03b ca631f70 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/17 15:38 upstream 9afe652958c3 417d98fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/15 02:08 upstream 4774cfe3543a 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/14 22:43 upstream 4774cfe3543a 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/14 13:14 upstream 4774cfe3543a 0e8da31f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/13 19:36 upstream 02adc1490e6d 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/13 19:34 upstream 02adc1490e6d 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/12 11:07 upstream 2c4a1f3fe03e 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/10 15:04 upstream f09079bd04a9 5d7e17ca .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/09 18:51 upstream 19272b37aa4f 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/09 16:15 upstream 19272b37aa4f 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/06 12:35 upstream e271ed52b344 f61267d4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/06 12:33 upstream e271ed52b344 f61267d4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/03 15:52 upstream 546b1c9e93c2 a30356b7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/03 13:38 upstream 546b1c9e93c2 a30356b7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/03 07:45 upstream 7f9039c524a3 b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/03 07:26 upstream 7f9039c524a3 b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/02 08:11 upstream bb1556ec9464 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/01 23:18 upstream 7d4e49a77d99 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/01 18:05 upstream 7d4e49a77d99 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/01 11:48 upstream 4cb6c8af8591 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/20 22:17 upstream 75f5f23f8787 e3003213 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/30 06:16 net 2def09ead4ad fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/15 21:59 net 5466491c9e33 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/13 17:54 net 5466491c9e33 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/27 10:18 net-next 28aa52b6189f 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/04 20:00 net-next 90b83efa6701 fd5e6e61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/03 02:42 net-next 90b83efa6701 b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/04 18:25 linux-next 911483b25612 fd5e6e61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/03 13:46 linux-next a0bea9e39035 a30356b7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/06/03 07:03 linux-next 3a83b350b5be b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/05/30 11:48 linux-next 3a83b350b5be 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/05/30 11:46 linux-next 3a83b350b5be 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
2025/05/30 07:10 linux-next 3a83b350b5be 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in exit_to_user_mode_loop
* Struck through repros no longer work on HEAD.