[syzbot] [bcachefs?] WARNING in bchfs_truncate

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3d25a941ea50 Merge tag 'block-6.9-20240503' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10e71b9b180000
kernel config: https://syzkaller.appspot.com/x/.config?x=3310e643b6ef5d69
dashboard link: https://syzkaller.appspot.com/bug?extid=247ac87eabcb1f8fa990
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a743748c2da4/disk-3d25a941.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9a51bb4cf9ba/vmlinux-3d25a941.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f4a1ba4b268a/bzImage-3d25a941.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+247ac8...@syzkaller.appspotmail.com

------------[ cut here ]------------
truncate spotted in mem i_size < btree i_size: 4 < 65536
WARNING: CPU: 0 PID: 29645 at fs/bcachefs/fs-io.c:434 bchfs_truncate+0x7ad/0xd70 fs/bcachefs/fs-io.c:434
Modules linked in:
CPU: 0 PID: 29645 Comm: syz-executor.3 Not tainted 6.9.0-rc6-syzkaller-00227-g3d25a941ea50 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:bchfs_truncate+0x7ad/0xd70 fs/bcachefs/fs-io.c:434
Code: 24 38 84 c0 0f 85 d3 fc ff ff e8 7e 4b 8e fd c6 05 91 7f 89 0b 01 90 48 c7 c7 80 52 5f 8b 4c 89 ea 4c 89 fe e8 14 b6 50 fd 90 <0f> 0b 90 90 48 b8 00 00 00 00 00 fc ff df 48 8b 54 24 48 48 c1 ea
RSP: 0018:ffffc900032d7758 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888064756cf8 RCX: ffffc9000c7d0000
RDX: 0000000000040000 RSI: ffffffff81503286 RDI: 0000000000000001
RBP: ffffc900032d7920 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 000000000008d6b8 R12: ffff8880647567b0
R13: 0000000000010000 R14: ffffc900032d7a18 R15: 0000000000000004
FS: 00007fb75c3de6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020ee5000 CR3: 000000002ac62000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
bch2_setattr+0x1ab/0x250 fs/bcachefs/fs.c:882
notify_change+0x742/0x11c0 fs/attr.c:497
do_truncate+0x15c/0x220 fs/open.c:65
handle_truncate fs/namei.c:3300 [inline]
do_open fs/namei.c:3646 [inline]
path_openat+0x24b9/0x2990 fs/namei.c:3799
do_filp_open+0x1dc/0x430 fs/namei.c:3826
do_sys_openat2+0x17a/0x1e0 fs/open.c:1406
do_sys_open fs/open.c:1421 [inline]
__do_sys_open fs/open.c:1429 [inline]
__se_sys_open fs/open.c:1425 [inline]
__x64_sys_open+0x154/0x1e0 fs/open.c:1425
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb75c87dca9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb75c3de0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fb75c9ac050 RCX: 00007fb75c87dca9
RDX: 0000000000000000 RSI: 000000000014927e RDI: 0000000020000180
RBP: 00007fb75c8c947e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb75c9ac050 R15: 00007ffdfe29fbb8
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: b6394d6f7159 Merge tag 'pull-misc' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=159d0210980000
kernel config: https://syzkaller.appspot.com/x/.config?x=713476114e57eef3
dashboard link: https://syzkaller.appspot.com/bug?extid=247ac87eabcb1f8fa990
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c61a0c980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e8e1377d4772/disk-b6394d6f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/19fbbb3b6dd5/vmlinux-b6394d6f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4dcce16af95d/bzImage-b6394d6f.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/fea098faf1eb/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+247ac8...@syzkaller.appspotmail.com

bcachefs (loop2): resume_logged_ops... done
bcachefs (loop2): going read-write
bcachefs (loop2): done starting filesystem
------------[ cut here ]------------
truncate spotted in mem i_size < btree i_size: 1 < 33554432
WARNING: CPU: 0 PID: 15517 at fs/bcachefs/fs-io.c:440 bchfs_truncate+0xb79/0xc80 fs/bcachefs/fs-io.c:437
Modules linked in:
CPU: 0 PID: 15517 Comm: syz-executor.2 Not tainted 6.9.0-syzkaller-10729-gb6394d6f7159 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:bchfs_truncate+0xb79/0xc80 fs/bcachefs/fs-io.c:437
Code: 00 fc ff df 80 3c 03 00 74 08 4c 89 e7 e8 ff 28 d2 fd 48 8b 94 24 f8 00 00 00 48 c7 c7 00 98 12 8c 4c 89 f6 e8 38 b9 31 fd 90 <0f> 0b 90 90 e9 8c f9 ff ff e8 39 9f 6f fd 48 8b 5c 24 60 48 89 df
RSP: 0018:ffffc900038c7520 EFLAGS: 00010246
RAX: c2b55e02655caf00 RBX: 1ffff92000718ec3 RCX: ffff88807bd6da00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900038c7758 R08: ffffffff815856f2 R09: fffffbfff1c3996c
R10: dffffc0000000000 R11: fffffbfff1c3996c R12: ffffc900038c7618
R13: ffff8880772676d0 R14: 0000000000000001 R15: ffff888077267bc8
FS: 00007f7f358766c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007fe610e2e6c0 CR3: 00000000ac338000 CR4: 00000000003506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>

notify_change+0xb9d/0xe70 fs/attr.c:497
do_truncate+0x220/0x310 fs/open.c:65
handle_truncate fs/namei.c:3308 [inline]
do_open fs/namei.c:3654 [inline]
path_openat+0x2a3d/0x3280 fs/namei.c:3807
do_filp_open+0x235/0x490 fs/namei.c:3834
do_sys_openat2+0x13e/0x1d0 fs/open.c:1405
do_sys_open fs/open.c:1420 [inline]
__do_sys_openat fs/open.c:1436 [inline]
__se_sys_openat fs/open.c:1431 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1431
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7f34a7cee9

Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007f7f358760c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f7f34babf80 RCX: 00007f7f34a7cee9
RDX: 000000000000275a RSI: 0000000020000280 RDI: ffffffffffffff9c
RBP: 00007f7f34ac949e R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 000000000000000b R14: 00007f7f34babf80 R15: 00007ffcb18bb738
</TASK>


---
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.

[syzbot]

syzbot has bisected this issue to:

commit 03ef80b469d5d83530ce1ce15be78a40e5300f9b
Author: Kent Overstreet <kent.ov...@linux.dev>
Date: Sat Sep 23 22:41:51 2023 +0000

bcachefs: Ignore unknown mount options

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1077cf8a980000
start commit: b6394d6f7159 Merge tag 'pull-misc' of git://git.kernel.org..
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=1277cf8a980000
console output: https://syzkaller.appspot.com/x/log.txt?x=1477cf8a980000

kernel config: https://syzkaller.appspot.com/x/.config?x=713476114e57eef3
dashboard link: https://syzkaller.appspot.com/bug?extid=247ac87eabcb1f8fa990

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c61a0c980000

Reported-by: syzbot+247ac8...@syzkaller.appspotmail.com
Fixes: 03ef80b469d5 ("bcachefs: Ignore unknown mount options")

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