linux-kernel - Re: [syzbot] [bcachefs?] kernel BUG in __bch2_trans

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <68a9fbde.050a0220.37038e.0067.GAE@google.com>
Date: Sat, 23 Aug 2025 10:35:26 -0700
From: syzbot <syzbot+b6ef9edaba01d5b4e43f@...kaller.appspotmail.com>
To: kent.overstreet@...ux.dev, linux-bcachefs@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [bcachefs?] kernel BUG in __bch2_trans_commit (3)

syzbot has found a reproducer for the following issue on:

HEAD commit:    8f5ae30d69d7 Linux 6.17-rc1
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=1157bfa2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5ac3d8b8abfcb
dashboard link: https://syzkaller.appspot.com/bug?extid=b6ef9edaba01d5b4e43f
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1424cc42580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1120a7bc580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/18a2e4bd0c4a/disk-8f5ae30d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3b5395881b25/vmlinux-8f5ae30d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e875f4e3b7ff/Image-8f5ae30d.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/42de714fb1cc/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b6ef9edaba01d5b4e43f@...kaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/bcachefs/btree_trans_commit.c:348!
Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
Modules linked in:
CPU: 1 UID: 0 PID: 15 Comm: kworker/u8:1 Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Workqueue: writeback wb_workfn (flush-bcachefs-1)
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : btree_insert_entry_checks fs/bcachefs/btree_trans_commit.c:343 [inline]
pc : bch2_trans_commit_write_locked fs/bcachefs/btree_trans_commit.c:725 [inline]
pc : do_bch2_trans_commit fs/bcachefs/btree_trans_commit.c:854 [inline]
pc : __bch2_trans_commit+0x6054/0x625c fs/bcachefs/btree_trans_commit.c:1085
lr : btree_insert_entry_checks fs/bcachefs/btree_trans_commit.c:343 [inline]
lr : bch2_trans_commit_write_locked fs/bcachefs/btree_trans_commit.c:725 [inline]
lr : do_bch2_trans_commit fs/bcachefs/btree_trans_commit.c:854 [inline]
lr : __bch2_trans_commit+0x6054/0x625c fs/bcachefs/btree_trans_commit.c:1085
sp : ffff800097c46c40
x29: ffff800097c46f60 x28: 00000000ffffffff x27: ffff0000cbb7e4d8
x26: ffff800092df2000 x25: 0000000000000000 x24: dfff800000000000
x23: ffff800092df2000 x22: ffff0000cbb7c020 x21: ffff0000cbb7c042
x20: 0000000000000001 x19: 0000000000000001 x18: 00000000ffffffff
x17: ffff800093507000 x16: ffff80008b007340 x15: 0000000000000002
x14: 1ffff00012f88cb0 x13: 0000000000000000 x12: 0000000000000000
x11: 00000000eacee03a x10: 0000000000ff0100 x9 : 0000000000000000
x8 : ffff0000c1a03d00 x7 : ffff8000828f3158 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000008 x1 : 0000000000000080 x0 : ffff0000c1a03d00
Call trace:
 btree_insert_entry_checks fs/bcachefs/btree_trans_commit.c:343 [inline] (P)
 bch2_trans_commit_write_locked fs/bcachefs/btree_trans_commit.c:725 [inline] (P)
 do_bch2_trans_commit fs/bcachefs/btree_trans_commit.c:854 [inline] (P)
 __bch2_trans_commit+0x6054/0x625c fs/bcachefs/btree_trans_commit.c:1085 (P)
 bch2_trans_commit fs/bcachefs/btree_update.h:241 [inline]
 bch2_write_inode+0x52c/0x92c fs/bcachefs/fs.c:136
 bch2_vfs_write_inode+0x84/0xcc fs/bcachefs/fs.c:2148
 write_inode fs/fs-writeback.c:1525 [inline]
 __writeback_single_inode+0x5ac/0x13e8 fs/fs-writeback.c:1745
 writeback_sb_inodes+0x55c/0xe40 fs/fs-writeback.c:1976
 wb_writeback+0x3cc/0xd70 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x338/0xdc0 fs/fs-writeback.c:2343
 process_one_work+0x7e8/0x155c kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x958/0xed8 kernel/workqueue.c:3400
 kthread+0x5fc/0x75c kernel/kthread.c:463
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844
Code: f940abe0 978e09e2 17ffffe0 97790f85 (d4210000) 
---[ end trace 0000000000000000 ]---


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.