syzbot


BUG: sleeping function called from invalid context in __lookup_slow

Status: upstream: reported C repro on 2026/01/28 07:09
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+5fb3bdc9a852ff2f43e7@syzkaller.appspotmail.com
First crash: 9d19h, last: 9d09h
Bug presence (2)
Date Name Commit Repro Result
2026/01/28 linux-5.15.y (ToT) 9eec9a14ee10 C [report] BUG: sleeping function called from invalid context in __lookup_slow
2026/01/28 upstream (ToT) 1f97d9dcf536 C Didn't crash
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2026/01/29 21:23 1m 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.
erofs: (device loop0): z_erofs_readpage: failed to read, err [-95]
BUG: sleeping function called from invalid context at fs/dcache.c:877
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 4314, name: syz.0.17
1 lock held by syz.0.17/4314:
 #0: ffff88805cd80180 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88805cd80180 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
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
CPU: 1 PID: 4314 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
 ___might_sleep+0x493/0x610 kernel/sched/core.c:9658
 dput+0x26/0x1a0 fs/dcache.c:877
 __lookup_slow+0x398/0x410 fs/namei.c:1674
 lookup_slow+0x53/0x70 fs/namei.c:1688
 walk_component+0x319/0x460 fs/namei.c:1984
 link_path_walk+0x665/0xd70 fs/namei.c:-1
 path_parentat fs/namei.c:2510 [inline]
 __filename_parentat+0x252/0x690 fs/namei.c:2534
 filename_parentat fs/namei.c:2552 [inline]
 filename_create+0xd5/0x470 fs/namei.c:3824
 do_mkdirat+0xa5/0x5b0 fs/namei.c:4088
 __do_sys_mkdirat fs/namei.c:4113 [inline]
 __se_sys_mkdirat fs/namei.c:4111 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111
 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: 0033:0x7fd6277ebeb9
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:00007ffe9dd21d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fd627a66fa0 RCX: 00007fd6277ebeb9
RDX: 00000000000001ff RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007fd627859c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd627a66fac R14: 00007fd627a66fa0 R15: 00007fd627a66fa0
 </TASK>
BUG: scheduling while atomic: syz.0.17/4314/0x00000002
no locks held by syz.0.17/4314.
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

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/28 10:37 linux-5.15.y 9eec9a14ee10 3029c699 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan BUG: sleeping function called from invalid context in __lookup_slow
2026/01/28 07:08 linux-5.15.y 9eec9a14ee10 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: sleeping function called from invalid context in __lookup_slow
2026/01/28 07:08 linux-5.15.y 9eec9a14ee10 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan BUG: sleeping function called from invalid context in __lookup_slow
* Struck through repros no longer work on HEAD.