syzbot


BUG: scheduling while atomic in exit_to_user_mode_loop (2)

Status: upstream: reported C repro on 2026/01/25 08:39
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+9a2d4d61e9055bfb3418@syzkaller.appspotmail.com
First crash: 1d06h, last: 1d04h
Bug presence (2)
Date Name Commit Repro Result
2026/01/25 linux-5.15.y (ToT) 9eec9a14ee10 C [report] BUG: scheduling while atomic in exit_to_user_mode_loop
2026/01/25 upstream (ToT) d91a46d6805a C Didn't crash
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: scheduling while atomic in exit_to_user_mode_loop ntfs3 5 syz error error 1 1178d 1205d 0/29 auto-obsoleted due to no activity on 2023/05/14 09:44
linux-6.1 BUG: scheduling while atomic in exit_to_user_mode_loop origin:lts-only 5 C done 3 705d 758d 0/3 upstream: reported C repro on 2023/12/30 14:50
android-5-15 BUG: scheduling while atomic in exit_to_user_mode_loop origin:upstream 5 C done 843 1d05h 758d 0/2 upstream: reported C repro on 2023/12/30 11:04
android-6-1 BUG: scheduling while atomic in exit_to_user_mode_loop 5 C done 1087 576d 758d 0/2 auto-obsoleted due to no activity on 2024/09/07 07:43
linux-5.15 BUG: scheduling while atomic in exit_to_user_mode_loop origin:lts-only 5 syz unreliable 2 707d 713d 0/3 auto-obsoleted due to no activity on 2024/10/07 06:36
android-5-10 BUG: scheduling while atomic in exit_to_user_mode_loop 5 C 33 1d13h 246d 0/2 upstream: reported C repro on 2025/05/25 06:17
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2026/01/25 18:22 3m fix candidate upstream error job log

Sample crash report:
loop0: detected capacity change from 0 to 16
erofs: (device loop0): mounted with root inode @ nid 36.
BUG: scheduling while atomic: syz.0.17/4319/0x00000002
no locks held by syz.0.17/4319.
Modules linked in:
Preemption disabled at:
[<ffffffff83990d27>] kmap_atomic include/linux/highmem-internal.h:196 [inline]
[<ffffffff83990d27>] z_erofs_reload_indexes+0x347/0x590 fs/erofs/zmap.c:146
Kernel panic - not syncing: scheduling while atomic: panic_on_warn set ...
CPU: 0 PID: 4319 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 panic+0x2e5/0x810 kernel/panic.c:309
 check_panic_on_warn+0x80/0xa0 kernel/panic.c:229
 __schedule_bug+0x193/0x1f0 kernel/sched/core.c:5589
 schedule_debug kernel/sched/core.c:5618 [inline]
 __schedule+0x1324/0x43c0 kernel/sched/core.c:6286
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 exit_to_user_mode_loop+0x47/0x130 kernel/entry/common.c:169
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1a6303ecb9
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:00007f1a626a20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f1a632b9fa8 RCX: 00007f1a6303ecb9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f1a632b9fac
RBP: 00007f1a632b9fa0 R08: 0039db51fbd66196 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1a632ba038 R14: 00007ffd59d0bca0 R15: 00007ffd59d0bd88
 </TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/25 09:31 linux-5.15.y 9eec9a14ee10 40acda8a .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan BUG: scheduling while atomic in exit_to_user_mode_loop
2026/01/25 09:00 linux-5.15.y 9eec9a14ee10 40acda8a .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan BUG: scheduling while atomic in exit_to_user_mode_loop
2026/01/25 08:38 linux-5.15.y 9eec9a14ee10 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: scheduling while atomic in exit_to_user_mode_loop
2026/01/25 08:38 linux-5.15.y 9eec9a14ee10 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: scheduling while atomic in exit_to_user_mode_loop
* Struck through repros no longer work on HEAD.