From: syzbot ci <syzbot+cib6a48fc441f958bd@syzkaller.appspotmail.com>
To: adilger.kernel@dilger.ca, albinbabuvarghese20@gmail.com,
david.hunter.linux@gmail.com, eraykrdg1@gmail.com,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
skhan@linuxfoundation.org, syzbot@syzkaller.appspotmail.com,
tytso@mit.edu
Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com
Subject: [syzbot ci] Re: ext4: fix unaligned preallocation with bigalloc
Date: Fri, 21 Nov 2025 01:14:00 -0800 [thread overview]
Message-ID: <69202d58.a70a0220.2ea503.004a.GAE@google.com> (raw)
In-Reply-To: <20251121002209.416949-2-eraykrdg1@gmail.com>
syzbot ci has tested the following series
[v1] ext4: fix unaligned preallocation with bigalloc
https://lore.kernel.org/all/20251121002209.416949-2-eraykrdg1@gmail.com
* [PATCH] ext4: fix unaligned preallocation with bigalloc
and found the following issue:
kernel BUG in ext4_mb_new_inode_pa
Full report is available here:
https://ci.syzbot.org/series/5fbb06a2-0d5c-4936-94b6-d73abad55373
***
kernel BUG in ext4_mb_new_inode_pa
tree: torvalds
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base: 23cb64fb76257309e396ea4cec8396d4a1dbae68
arch: amd64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config: https://ci.syzbot.org/builds/3beb0e0f-6449-481d-8a5c-870149d28caf/config
C repro: https://ci.syzbot.org/findings/891b93f7-ef7e-4890-8c4b-ed438fa3fa28/c_repro
syz repro: https://ci.syzbot.org/findings/891b93f7-ef7e-4890-8c4b-ed438fa3fa28/syz_repro
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
------------[ cut here ]------------
kernel BUG at fs/ext4/mballoc.c:5312!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 5990 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:ext4_mb_new_inode_pa+0x144e/0x1520 fs/ext4/mballoc.c:5312
Code: 5d 04 00 eb 2c e8 42 d8 43 ff 90 0f 0b e8 3a d8 43 ff 90 0f 0b e8 32 d8 43 ff eb 3c e8 2b d8 43 ff 90 0f 0b e8 23 d8 43 ff 90 <0f> 0b e8 1b d8 43 ff 31 f6 65 ff 0d 82 24 f2 0f 0f 94 c3 40 0f 94
RSP: 0018:ffffc900037c6a88 EFLAGS: 00010293
RAX: ffffffff827c2b9d RBX: 0000000000000201 RCX: ffff8881ba628000
RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000210
RBP: 0000000000000190 R08: ffffea000418ec37 R09: 1ffffd4000831d86
R10: dffffc0000000000 R11: fffff94000831d87 R12: 0000000000000004
R13: ffff88801b03f2b8 R14: dffffc0000000000 R15: 0000000000000210
FS: 0000555557696500(0000) GS:ffff88818eb3b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f863fff CR3: 000000016b520000 CR4: 00000000000006f0
Call Trace:
<TASK>
ext4_mb_try_best_found+0x33e/0x440 fs/ext4/mballoc.c:2389
ext4_mb_regular_allocator+0x9fa/0x2970 fs/ext4/mballoc.c:3040
ext4_mb_new_blocks+0xd11/0x4720 fs/ext4/mballoc.c:6319
ext4_ext_map_blocks+0x161a/0x6ac0 fs/ext4/extents.c:4383
ext4_map_create_blocks fs/ext4/inode.c:609 [inline]
ext4_map_blocks+0x860/0x1740 fs/ext4/inode.c:811
_ext4_get_block+0x200/0x4c0 fs/ext4/inode.c:910
ext4_get_block_unwritten+0x2e/0x100 fs/ext4/inode.c:943
ext4_block_write_begin+0x993/0x1710 fs/ext4/inode.c:1198
ext4_write_begin+0xc04/0x19a0 fs/ext4/ext4_jbd2.h:-1
ext4_da_write_begin+0x445/0xda0 fs/ext4/inode.c:3129
generic_perform_write+0x2c5/0x900 mm/filemap.c:4254
ext4_buffered_write_iter+0xce/0x3a0 fs/ext4/file.c:299
ext4_file_write_iter+0x298/0x1bc0 fs/ext4/file.c:-1
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_pwrite64 fs/read_write.c:793 [inline]
__do_sys_pwrite64 fs/read_write.c:801 [inline]
__se_sys_pwrite64 fs/read_write.c:798 [inline]
__x64_sys_pwrite64+0x193/0x220 fs/read_write.c:798
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3f2c38f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff15880d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f3f2c5e5fa0 RCX: 00007f3f2c38f6c9
RDX: 0000000000000001 RSI: 00002000000005c0 RDI: 0000000000000004
RBP: 00007f3f2c411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000004fed0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3f2c5e5fa0 R14: 00007f3f2c5e5fa0 R15: 0000000000000004
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_mb_new_inode_pa+0x144e/0x1520 fs/ext4/mballoc.c:5312
Code: 5d 04 00 eb 2c e8 42 d8 43 ff 90 0f 0b e8 3a d8 43 ff 90 0f 0b e8 32 d8 43 ff eb 3c e8 2b d8 43 ff 90 0f 0b e8 23 d8 43 ff 90 <0f> 0b e8 1b d8 43 ff 31 f6 65 ff 0d 82 24 f2 0f 0f 94 c3 40 0f 94
RSP: 0018:ffffc900037c6a88 EFLAGS: 00010293
RAX: ffffffff827c2b9d RBX: 0000000000000201 RCX: ffff8881ba628000
RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000210
RBP: 0000000000000190 R08: ffffea000418ec37 R09: 1ffffd4000831d86
R10: dffffc0000000000 R11: fffff94000831d87 R12: 0000000000000004
R13: ffff88801b03f2b8 R14: dffffc0000000000 R15: 0000000000000210
FS: 0000555557696500(0000) GS:ffff88818eb3b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f863fff CR3: 000000016b520000 CR4: 00000000000006f0
***
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.
next prev parent reply other threads:[~2025-11-21 9:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-21 0:22 [PATCH] ext4: fix unaligned preallocation with bigalloc Ahmet Eray Karadag
2025-11-21 9:14 ` syzbot ci [this message]
2025-11-22 2:45 ` [PATCH v2] " Ahmet Eray Karadag
2025-11-22 8:55 ` [syzbot ci] " syzbot ci
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