[v5.15] BUG: sleeping function called from invalid context in path_openat

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9eec9a14ee10 Linux 5.15.198
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12c1305a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=5db97d552bbbb3e5779d
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7146a7b4242e/disk-9eec9a14.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a11468b96c22/vmlinux-9eec9a14.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e7cb8f058e1c/bzImage-9eec9a14.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5db97d...@syzkaller.appspotmail.com

loop2: detected capacity change from 0 to 16
erofs: (device loop2): mounted with root inode @ nid 36.
erofs: (device loop2): 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: 5565, name: syz.2.266
1 lock held by syz.2.266/5565:
#0: ffff888056c546c0 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#0: ffff888056c546c0 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: open_last_lookups fs/namei.c:3537 [inline]
#0: ffff888056c546c0 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: path_openat+0x803/0x2fa0 fs/namei.c:3747
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: 0 PID: 5565 Comm: syz.2.266 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_open fs/namei.c:3482 [inline]
open_last_lookups fs/namei.c:3540 [inline]
path_openat+0x1207/0x2fa0 fs/namei.c:3747
do_filp_open+0x1e2/0x410 fs/namei.c:3777
do_sys_openat2+0x150/0x4b0 fs/open.c:1255
do_sys_open fs/open.c:1271 [inline]
__do_sys_openat fs/open.c:1287 [inline]
__se_sys_openat fs/open.c:1282 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1282
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: 0033:0x7f03c14d1cb9
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:00007f03bf72d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f03c174cfa0 RCX: 00007f03c14d1cb9
RDX: 000000000000275a RSI: 00002000000001c0 RDI: ffffffffffffff9c
RBP: 00007f03c153fbf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f03c174d038 R14: 00007f03c174cfa0 R15: 00007fff66e46c68
</TASK>
BUG: scheduling while atomic: syz.2.266/5565/0x00000002
no locks held by syz.2.266/5565.
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


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 9eec9a14ee10 Linux 5.15.198
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=156ef52a580000

kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=5db97d552bbbb3e5779d
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=163e368a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10814002580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7146a7b4242e/disk-9eec9a14.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a11468b96c22/vmlinux-9eec9a14.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e7cb8f058e1c/bzImage-9eec9a14.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/3aab5a11b2bf/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=15032452580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5db97d...@syzkaller.appspotmail.com

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: 4349, name: syz.0.17
1 lock held by syz.0.17/4349:
#0: ffff88805a88c180 (&type->i_mutex_dir_key#8){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#0: ffff88805a88c180 (&type->i_mutex_dir_key#8){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3537 [inline]
#0: ffff88805a88c180 (&type->i_mutex_dir_key#8){+.+.}-{3:3}, at: path_openat+0x803/0x2fa0 fs/namei.c:3747

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: 0 PID: 4349 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_open fs/namei.c:3482 [inline]
open_last_lookups fs/namei.c:3540 [inline]
path_openat+0x1207/0x2fa0 fs/namei.c:3747
do_filp_open+0x1e2/0x410 fs/namei.c:3777
do_sys_openat2+0x150/0x4b0 fs/open.c:1255
do_sys_open fs/open.c:1271 [inline]
__do_sys_openat fs/open.c:1287 [inline]
__se_sys_openat fs/open.c:1282 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1282
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: 0033:0x7f7eaf497cb9

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:00007ffce35462b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f7eaf712fa0 RCX: 00007f7eaf497cb9

RDX: 000000000000275a RSI: 00002000000001c0 RDI: ffffffffffffff9c

RBP: 00007f7eaf505bf7 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007f7eaf712fac R14: 00007f7eaf712fa0 R15: 00007f7eaf712fa0
</TASK>
BUG: scheduling while atomic: syz.0.17/4349/0x00000002
no locks held by syz.0.17/4349.

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


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