[syzbot] [mm?] [ext4?] WARNING in ext4_init_orphan_info

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 76eeb9b8de98 Linux 6.17-rc5
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12ca0934580000
kernel config: https://syzkaller.appspot.com/x/.config?x=429771c55b615e85
dashboard link: https://syzkaller.appspot.com/bug?extid=0b92850d68d9b12934f5
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=168d2562580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15869562580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eee687cc7d76/disk-76eeb9b8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4062cd7a7107/vmlinux-76eeb9b8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3bcb5a03c247/bzImage-76eeb9b8.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/7e09a33c999c/mount_0.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=140df312580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0b9285...@syzkaller.appspotmail.com

EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!
EXT4-fs (loop0): encrypted files will use data=ordered instead of data journaling mode
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6103 at mm/page_alloc.c:5124 __alloc_frozen_pages_noprof+0x2c8/0x370 mm/page_alloc.c:5124
Modules linked in:
CPU: 0 UID: 0 PID: 6103 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__alloc_frozen_pages_noprof+0x2c8/0x370 mm/page_alloc.c:5124
Code: 74 10 4c 89 e7 89 54 24 0c e8 24 e2 0c 00 8b 54 24 0c 49 83 3c 24 00 0f 85 a5 fe ff ff e9 a6 fe ff ff c6 05 a6 ac f6 0c 01 90 <0f> 0b 90 e9 18 ff ff ff a9 00 00 08 00 48 8b 4c 24 10 4c 8d 44 24
RSP: 0018:ffffc900047676a0 EFLAGS: 00010246
RAX: ffffc90004767600 RBX: 000000000000000e RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90004767708
RBP: ffffc900047677a0 R08: ffffc90004767707 R09: 0000000000000000
R10: ffffc900047676e0 R11: fffff520008ecee1 R12: 0000000000000000
R13: 1ffff920008eced8 R14: 0000000000040cc0 R15: dffffc0000000000
FS: 000055556bfce500(0000) GS:ffff8881268bf000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f54f6aba6b0 CR3: 000000003b292000 CR4: 00000000003526f0
Call Trace:
<TASK>
alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416
___kmalloc_large_node+0x5f/0x1b0 mm/slub.c:4317
__kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:4348
__do_kmalloc_node mm/slub.c:4364 [inline]
__kmalloc_noprof+0x27a/0x430 mm/slub.c:4388
kmalloc_noprof include/linux/slab.h:909 [inline]
kmalloc_array_noprof include/linux/slab.h:948 [inline]
ext4_init_orphan_info+0x2b7/0xc70 fs/ext4/orphan.c:592
__ext4_fill_super fs/ext4/super.c:5590 [inline]
ext4_fill_super+0x55ef/0x60b0 fs/ext4/super.c:5728
get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbc7ab6038a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffed38a5318 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffed38a53a0 RCX: 00007fbc7ab6038a
RDX: 0000200000000040 RSI: 00002000000001c0 RDI: 00007ffed38a5360
RBP: 0000200000000040 R08: 00007ffed38a53a0 R09: 0000000000000c04
R10: 0000000000000c04 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007ffed38a5360 R14: 0000000000000448 R15: 0000200000000580
</TASK>


---
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[syzbot]

syzbot has bisected this issue to:

commit 02f310fcf47fa9311d6ba2946a8d19e7d7d11f37
Author: Jan Kara <ja...@suse.cz>
Date: Mon Aug 16 09:57:06 2021 +0000

ext4: Speedup ext4 orphan inode handling

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16645562580000
start commit: 76eeb9b8de98 Linux 6.17-rc5
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=15645562580000
console output: https://syzkaller.appspot.com/x/log.txt?x=11645562580000

kernel config: https://syzkaller.appspot.com/x/.config?x=429771c55b615e85
dashboard link: https://syzkaller.appspot.com/bug?extid=0b92850d68d9b12934f5

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=168d2562580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15869562580000

Reported-by: syzbot+0b9285...@syzkaller.appspotmail.com
Fixes: 02f310fcf47f ("ext4: Speedup ext4 orphan inode handling")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Jan Kara]

Hum, yes, we don't verify orphan file size is sane. I'll send a fix.

Honza

--
Jan Kara <ja...@suse.com>
SUSE Labs, CR