Re: [syzbot] [ext4?] kernel BUG in ext4_mb_use_inode_pa (2)

From: syzbot
Date: Fri Sep 06 2024 - 00:42:32 EST


syzbot has found a reproducer for the following issue on:

HEAD commit: ad618736883b Merge tag 'platform-drivers-x86-v6.11-6' of g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14fc4397980000
kernel config: https://syzkaller.appspot.com/x/.config?x=660f6eb11f9c7dc5
dashboard link: https://syzkaller.appspot.com/bug?extid=d79019213609e7056a19
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=16691fdb980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1067bd97980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-ad618736.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5d2517f4cb56/vmlinux-ad618736.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0979c5ca28c2/bzImage-ad618736.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/043e7c757d36/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d79019213609e7056a19@xxxxxxxxxxxxxxxxxxxxxxxxx

EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
loop0: detected capacity change from 512 to 64
------------[ cut here ]------------
kernel BUG at fs/ext4/mballoc.c:4689!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5093 Comm: syz-executor323 Not tainted 6.11.0-rc6-syzkaller-00075-gad618736883b #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:ext4_mb_use_inode_pa+0x690/0x700 fs/ext4/mballoc.c:4689
Code: 40 1d b0 8e 4c 89 e6 48 89 ea e8 fb c5 8b 02 e9 be fc ff ff e8 f1 05 33 ff 90 0f 0b e8 e9 05 33 ff 90 0f 0b e8 e1 05 33 ff 90 <0f> 0b e8 d9 05 33 ff 90 0f 0b 48 8b 0c 24 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc90002cde8e8 EFLAGS: 00010293
RAX: ffffffff826086cf RBX: 00000000fffffffe RCX: ffff88801edf2440
RDX: 0000000000000000 RSI: 0000000000000041 RDI: 000000000000003f
RBP: 0000000000000000 R08: ffffffff826083cf R09: 1ffff11003fcbd4e
R10: dffffc0000000000 R11: ffffed1003fcbd4f R12: ffff88801fe5ea88
R13: 1ffff110025a4181 R14: 0000000000000041 R15: 1ffff11003fcbd51
FS: 000055557d5ee380(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000f000 CR3: 0000000000b5c000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_mb_use_preallocated+0x680/0x1420 fs/ext4/mballoc.c:4906
ext4_mb_new_blocks+0x6ef/0x4e30 fs/ext4/mballoc.c:6210
ext4_alloc_branch fs/ext4/indirect.c:340 [inline]
ext4_ind_map_blocks+0x1084/0x2a10 fs/ext4/indirect.c:635
ext4_map_blocks+0x9f6/0x1d20 fs/ext4/inode.c:654
mpage_map_one_extent fs/ext4/inode.c:2237 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2290 [inline]
ext4_do_writepages+0x1605/0x3d40 fs/ext4/inode.c:2753
ext4_writepages+0x213/0x3c0 fs/ext4/inode.c:2842
do_writepages+0x35d/0x870 mm/page-writeback.c:2683
filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397
__filemap_fdatawrite_range mm/filemap.c:430 [inline]
file_write_and_wait_range+0x1aa/0x290 mm/filemap.c:788
generic_buffers_fsync_noflush+0x73/0x170 fs/buffer.c:600
ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
ext4_sync_file+0x413/0xb90 fs/ext4/fsync.c:151
generic_write_sync include/linux/fs.h:2822 [inline]
ext4_buffered_write_iter+0x286/0x350 fs/ext4/file.c:305
ext4_file_write_iter+0x1de/0x1a10
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xa72/0xc90 fs/read_write.c:590
ksys_pwrite64 fs/read_write.c:705 [inline]
__do_sys_pwrite64 fs/read_write.c:715 [inline]
__se_sys_pwrite64 fs/read_write.c:712 [inline]
__x64_sys_pwrite64+0x1aa/0x230 fs/read_write.c:712
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2de5ebcc59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdfe577c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2de5ebcc59
RDX: 000000000000fdef RSI: 0000000020000140 RDI: 0000000000000006
RBP: 00007f2de5f305f0 R08: 000055557d5ef4c0 R09: 000055557d5ef4c0
R10: 000000000000fecc R11: 0000000000000246 R12: 00007ffdfe577c80
R13: 00007ffdfe577ea8 R14: 431bde82d7b634db R15: 00007f2de5f0503b
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_mb_use_inode_pa+0x690/0x700 fs/ext4/mballoc.c:4689
Code: 40 1d b0 8e 4c 89 e6 48 89 ea e8 fb c5 8b 02 e9 be fc ff ff e8 f1 05 33 ff 90 0f 0b e8 e9 05 33 ff 90 0f 0b e8 e1 05 33 ff 90 <0f> 0b e8 d9 05 33 ff 90 0f 0b 48 8b 0c 24 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc90002cde8e8 EFLAGS: 00010293
RAX: ffffffff826086cf RBX: 00000000fffffffe RCX: ffff88801edf2440
RDX: 0000000000000000 RSI: 0000000000000041 RDI: 000000000000003f
RBP: 0000000000000000 R08: ffffffff826083cf R09: 1ffff11003fcbd4e
R10: dffffc0000000000 R11: ffffed1003fcbd4f R12: ffff88801fe5ea88
R13: 1ffff110025a4181 R14: 0000000000000041 R15: 1ffff11003fcbd51
FS: 000055557d5ee380(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000f000 CR3: 0000000000b5c000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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