[syzbot] [btrfs?] BUG: corrupted list in btrfs_free_compr_folio

[syzbot] [btrfs?] BUG: corrupted list in btrfs_free_compr_folio

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    f338e7738378 Linux 7.0-rc4
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15265602580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d46eab0cfd31c214
dashboard link: https://syzkaller.appspot.com/bug?extid=3c4d8371d65230f852a2
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 (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-f338e773.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2567fb35ebfb/vmlinux-f338e773.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f9124de81ddb/bzImage-f338e773.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3c4d8371d65230f852a2@syzkaller.appspotmail.com

list_add double add: new=ffffea00010a8488, prev=ffffffff9a43a948, next=ffffea00010a8488.
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:37!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 1045 Comm: kworker/u4:8 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: btrfs-delalloc btrfs_work_helper
RIP: 0010:__list_add_valid_or_report+0xa5/0x130 lib/list_debug.c:35
Code: 74 12 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d e9 12 c6 f8 06 cc 48 c7 c7 e0 d7 27 8c 4c 89 fe 4c 89 f2 48 89 d9 e8 5c 49 6d fc 90 <0f> 0b 48 c7 c7 c0 d5 27 8c e8 4d 49 6d fc 90 0f 0b 48 c7 c7 80 d6
RSP: 0018:ffffc90000d6f800 EFLAGS: 00010246
RAX: 0000000000000058 RBX: ffffea00010a8488 RCX: 9af6677df2ed2e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 1ffffd4000215092 R08: ffffc90000d6f587 R09: 1ffff920001adeb0
R10: dffffc0000000000 R11: fffff520001adeb1 R12: 1ffffffff3487529
R13: dffffc0000000000 R14: ffffffff9a43a948 R15: ffffea00010a8488
FS:  0000000000000000(0000) GS:ffff88808ca55000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e37eb87168 CR3: 0000000041bd8000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __list_add_valid include/linux/list.h:96 [inline]
 __list_add include/linux/list.h:158 [inline]
 list_add include/linux/list.h:177 [inline]
 btrfs_free_compr_folio+0x1e1/0x340 fs/btrfs/compression.c:218
 cleanup_compressed_bio fs/btrfs/compression.h:150 [inline]
 btrfs_compress_bio+0x35a/0x6b0 fs/btrfs/compression.c:1047
 compress_file_range+0x8df/0x19b0 fs/btrfs/inode.c:1023
 btrfs_work_helper+0x38c/0xc80 fs/btrfs/async-thread.c:312
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_add_valid_or_report+0xa5/0x130 lib/list_debug.c:35
Code: 74 12 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d e9 12 c6 f8 06 cc 48 c7 c7 e0 d7 27 8c 4c 89 fe 4c 89 f2 48 89 d9 e8 5c 49 6d fc 90 <0f> 0b 48 c7 c7 c0 d5 27 8c e8 4d 49 6d fc 90 0f 0b 48 c7 c7 80 d6
RSP: 0018:ffffc90000d6f800 EFLAGS: 00010246
RAX: 0000000000000058 RBX: ffffea00010a8488 RCX: 9af6677df2ed2e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 1ffffd4000215092 R08: ffffc90000d6f587 R09: 1ffff920001adeb0
R10: dffffc0000000000 R11: fffff520001adeb1 R12: 1ffffffff3487529
R13: dffffc0000000000 R14: ffffffff9a43a948 R15: ffffea00010a8488
FS:  0000000000000000(0000) GS:ffff88808ca55000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e37eb87168 CR3: 0000000041bd8000 CR4: 0000000000352ef0


---
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Re: [syzbot] [btrfs?] BUG: corrupted list in btrfs_free_compr_folio

[David Sterba]

On Mon, Mar 16, 2026 at 06:40:28AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    f338e7738378 Linux 7.0-rc4
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15265602580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d46eab0cfd31c214
> dashboard link: https://syzkaller.appspot.com/bug?extid=3c4d8371d65230f852a2
> 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 (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-f338e773.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/2567fb35ebfb/vmlinux-f338e773.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/f9124de81ddb/bzImage-f338e773.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+3c4d8371d65230f852a2@syzkaller.appspotmail.com

syz: fix: btrfs: zlib: handle page aligned compressed size correctly

Re: [syzbot] [btrfs?] BUG: corrupted list in btrfs_free_compr_folio

[Aleksandr Nogikh]

On Wed, Mar 18, 2026 at 5:35 PM David Sterba <dsterba@suse.cz> wrote:
>
> On Mon, Mar 16, 2026 at 06:40:28AM -0700, syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    f338e7738378 Linux 7.0-rc4
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=15265602580000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=d46eab0cfd31c214
> > dashboard link: https://syzkaller.appspot.com/bug?extid=3c4d8371d65230f852a2
> > 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 (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-f338e773.raw.xz
> > vmlinux: https://storage.googleapis.com/syzbot-assets/2567fb35ebfb/vmlinux-f338e773.xz
> > kernel image: https://storage.googleapis.com/syzbot-assets/f9124de81ddb/bzImage-f338e773.xz
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+3c4d8371d65230f852a2@syzkaller.appspotmail.com
>
> syz: fix: btrfs: zlib: handle page aligned compressed size correctly

#syz fix: btrfs: zlib: handle page aligned compressed size correctly