linux-kernel - [syzbot] [bcachefs?] kernel BUG in bch2_folio

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Message-ID: <68999af2.050a0220.51d73.009a.GAE@google.com>
Date: Mon, 11 Aug 2025 00:25:38 -0700
From: syzbot <syzbot+8397085af632792ccc3a@...kaller.appspotmail.com>
To: kent.overstreet@...ux.dev, linux-bcachefs@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [bcachefs?] kernel BUG in bch2_folio_set

Hello,

syzbot found the following issue on:

HEAD commit:    82af5ea7c611 Merge branch 'for-next/core' into for-kernelci
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=12b2c1a2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=71154cdde49ea192
dashboard link: https://syzkaller.appspot.com/bug?extid=8397085af632792ccc3a
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=16f6d5bc580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14c19434580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/dd1816edf6fa/disk-82af5ea7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/961cb9724207/vmlinux-82af5ea7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b93e015179fb/Image-82af5ea7.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/622cc58dab82/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8397085af632792ccc3a@...kaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/bcachefs/fs-io-pagecache.c:219!
Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
Modules linked in:
CPU: 0 UID: 0 PID: 6736 Comm: syz.0.17 Not tainted 6.16.0-rc7-syzkaller-g82af5ea7c611 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/18/2025
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : bch2_folio_set+0x940/0x964 fs/bcachefs/fs-io-pagecache.c:201
lr : bch2_folio_set+0x940/0x964 fs/bcachefs/fs-io-pagecache.c:201
sp : ffff8000a0767660
x29: ffff8000a0767800 x28: 0040000000000040 x27: 0040000000000040
x26: ffc0000000000038 x25: ffff8000a0767790 x24: dfff800000000000
x23: ffc0000100000037 x22: fffffdffc39e5208 x21: fffffdffc39e5200
x20: ffc0000000000038 x19: ffc0000000000038 x18: 00000000ffffffff
x17: ffff800080d32178 x16: ffff80008ae69508 x15: 0000000000000003
x14: 0000000000000000 x13: 0000000000000013 x12: 0000000000ff0100
x11: ffff0000da3c5b80 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : ffff0000da3c5b80 x7 : 20000000ffc00000 x6 : 00000038ffffffff
x5 : ffff8000a07677a0 x4 : ffff8000a0767774 x3 : 0000000000000000
x2 : ffff8000a0767778 x1 : 0040000000000040 x0 : ffc0000000000038
Call trace:
 bch2_folio_set+0x940/0x964 fs/bcachefs/fs-io-pagecache.c:201 (P)
 __bch2_buffered_write fs/bcachefs/fs-io-buffered.c:864 [inline]
 bch2_buffered_write fs/bcachefs/fs-io-buffered.c:1026 [inline]
 bch2_write_iter+0xa14/0x2300 fs/bcachefs/fs-io-buffered.c:1082
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x62c/0x97c fs/read_write.c:686
 ksys_write+0x120/0x210 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:746
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
Code: d4210000 9776de90 d4210000 9776de8e (d4210000) 
---[ end trace 0000000000000000 ]---


---
This report is generated by a bot. It may contain errors.
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