[v5.15] BUG: sleeping function called from invalid context in dput (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 68efe5a6c16a Linux 5.15.197
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15e26e1a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7e6ed99963d6ee1d
dashboard link: https://syzkaller.appspot.com/bug?extid=27e33caefe8ebf3df661
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/900f9b9bd850/disk-68efe5a6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1e089a5019a6/vmlinux-68efe5a6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b319f477b907/bzImage-68efe5a6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+27e33c...@syzkaller.appspotmail.com

loop3: detected capacity change from 0 to 16
erofs: (device loop3): mounted with root inode @ nid 36.
erofs: (device loop3): 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: 4394, name: syz.3.26
1 lock held by syz.3.26/4394:
#0: ffff88805e638180 (&type->i_mutex_dir_key#11/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
#0: ffff88805e638180 (&type->i_mutex_dir_key#11/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3843
Preemption disabled at:
[<ffffffff83912457>] kmap_atomic include/linux/highmem-internal.h:196 [inline]
[<ffffffff83912457>] z_erofs_reload_indexes+0x347/0x590 fs/erofs/zmap.c:146
CPU: 0 PID: 4394 Comm: syz.3.26 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
___might_sleep+0x47c/0x600 kernel/sched/core.c:9658
dput+0x26/0x1a0 fs/dcache.c:877
lookup_one_qstr_excl+0x1d6/0x240 fs/namei.c:1573
filename_create+0x21e/0x450 fs/namei.c:3844
do_mknodat+0x16e/0x620 fs/namei.c:3989
__do_sys_mknod fs/namei.c:4035 [inline]
__se_sys_mknod fs/namei.c:4033 [inline]
__x64_sys_mknod+0x8a/0xa0 fs/namei.c:4033
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: 0033:0x7f1c19e11749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1c18078038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f1c1a067fa0 RCX: 00007f1c19e11749
RDX: 0000000000000000 RSI: 000000000000c000 RDI: 0000200000000080
RBP: 00007f1c19e95f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1c1a068038 R14: 00007f1c1a067fa0 R15: 00007ffd8a904fc8
</TASK>
BUG: scheduling while atomic: syz.3.26/4394/0x00000002
no locks held by syz.3.26/4394.
Modules linked in:
Preemption disabled at:
[<ffffffff83912457>] kmap_atomic include/linux/highmem-internal.h:196 [inline]
[<ffffffff83912457>] 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: 68efe5a6c16a Linux 5.15.197
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=117661b4580000

kernel config: https://syzkaller.appspot.com/x/.config?x=7e6ed99963d6ee1d
dashboard link: https://syzkaller.appspot.com/bug?extid=27e33caefe8ebf3df661
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14666e1a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ddd592580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/900f9b9bd850/disk-68efe5a6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1e089a5019a6/vmlinux-68efe5a6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b319f477b907/bzImage-68efe5a6.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/0f5fc75328cc/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=10666e1a580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+27e33c...@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: 4321, name: syz.0.17
1 lock held by syz.0.17/4321:
#0: ffff88805c138180 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
#0: ffff88805c138180 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3843

Preemption disabled at:
[<ffffffff83912457>] kmap_atomic include/linux/highmem-internal.h:196 [inline]
[<ffffffff83912457>] z_erofs_reload_indexes+0x347/0x590 fs/erofs/zmap.c:146

CPU: 1 PID: 4321 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+0x168/0x230 lib/dump_stack.c:106
___might_sleep+0x47c/0x600 kernel/sched/core.c:9658
dput+0x26/0x1a0 fs/dcache.c:877
lookup_one_qstr_excl+0x1d6/0x240 fs/namei.c:1573
filename_create+0x21e/0x450 fs/namei.c:3844
do_mknodat+0x16e/0x620 fs/namei.c:3989
__do_sys_mknod fs/namei.c:4035 [inline]
__se_sys_mknod fs/namei.c:4033 [inline]
__x64_sys_mknod+0x8a/0xa0 fs/namei.c:4033
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: 0033:0x7fc57c7c4749

Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007fff6b1a7628 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007fc57ca1afa0 RCX: 00007fc57c7c4749

RDX: 0000000000000000 RSI: 000000000000c000 RDI: 0000200000000080

RBP: 00007fc57c848f91 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007fc57ca1afa0 R14: 00007fc57ca1afa0 R15: 0000000000000003
</TASK>
BUG: scheduling while atomic: syz.0.17/4321/0x00000002
no locks held by syz.0.17/4321.

Modules linked in:
Preemption disabled at:
[<ffffffff83912457>] kmap_atomic include/linux/highmem-internal.h:196 [inline]
[<ffffffff83912457>] z_erofs_reload_indexes+0x347/0x590 fs/erofs/zmap.c:146


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