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Date:   Mon, 12 Jun 2023 22:51:52 -0700
Message-ID: <00000000000099887f05fdfc6e10@google.com>
Subject: [syzbot] [ext4?] kernel BUG in ext4_split_extent_at (2)
From:   syzbot <syzbot+0f4d9f68fb6632330c6c@syzkaller.appspotmail.com>
To:     adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        syzkaller-bugs@googlegroups.com, tytso@mit.edu
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Precedence: bulk

Hello,

syzbot found the following issue on:

HEAD commit:    25041a4c02c7 Merge tag 'net-6.4-rc6' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12801759280000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7474de833c217bf4
dashboard link: https://syzkaller.appspot.com/bug?extid=0f4d9f68fb6632330c6c
compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11b3bc8d280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/164bca6d1fd9/disk-25041a4c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7522d0748e33/vmlinux-25041a4c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b32318c9ea13/bzImage-25041a4c.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/4bcaa768d65c/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0f4d9f68fb6632330c6c@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/ext4/ext4_extents.h:200!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5141 Comm: syz-executor.2 Not tainted 6.4.0-rc5-syzkaller-00133-g25041a4c02c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:ext4_ext_mark_unwritten fs/ext4/ext4_extents.h:200 [inline]
RIP: 0010:ext4_split_extent_at+0x10f0/0x1100 fs/ext4/extents.c:3221
Code: 4e ac ff 48 8b 54 24 70 48 8b 74 24 60 e9 3b fa ff ff e8 13 77 54 ff 0f 0b e8 0c 77 54 ff 0f 0b e8 c5 85 78 08 e8 00 77 54 ff <0f> 0b e8 f9 76 54 ff 0f 0b e8 f2 76 54 ff 0f 0b 55 41 57 41 56 41
RSP: 0018:ffffc9000432eec0 EFLAGS: 00010293

RAX: ffffffff82370830 RBX: 0000000000000000 RCX: ffff88807d9a9dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000432f028 R08: ffffffff8236fc0c R09: ffffed100eff1db4
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff88801e655d00 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f6fc7dd5700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002003f000 CR3: 000000007416c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_split_extent+0x370/0x4e0 fs/ext4/extents.c:3384
 ext4_split_convert_extents fs/ext4/extents.c:3713 [inline]
 ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3875 [inline]
 ext4_ext_map_blocks+0x22c9/0x7210 fs/ext4/extents.c:4167
 ext4_map_blocks+0xa4c/0x1cf0 fs/ext4/inode.c:623
 ext4_iomap_alloc fs/ext4/inode.c:3298 [inline]
 ext4_iomap_begin+0x8e4/0xd30 fs/ext4/inode.c:3348
 iomap_iter+0x677/0xec0 fs/iomap/iter.c:91
 __iomap_dio_rw+0xe1b/0x22e0 fs/iomap/direct-io.c:597
 iomap_dio_rw+0x46/0xa0 fs/iomap/direct-io.c:688
 ext4_dio_write_iter fs/ext4/file.c:597 [inline]
 ext4_file_write_iter+0x1509/0x1930 fs/ext4/file.c:708
 call_write_iter include/linux/fs.h:1868 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x790/0xb20 fs/read_write.c:584
 ksys_write+0x1a0/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f6fc708c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007f6fc7dd5168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6fc71ac050 RCX: 00007f6fc708c169
RDX: 0000000000000012 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007f6fc70e7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcf37a297f R14: 00007f6fc7dd5300 R15: 0000000000022000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_ext_mark_unwritten fs/ext4/ext4_extents.h:200 [inline]
RIP: 0010:ext4_split_extent_at+0x10f0/0x1100 fs/ext4/extents.c:3221
Code: 4e ac ff 48 8b 54 24 70 48 8b 74 24 60 e9 3b fa ff ff e8 13 77 54 ff 0f 0b e8 0c 77 54 ff 0f 0b e8 c5 85 78 08 e8 00 77 54 ff <0f> 0b e8 f9 76 54 ff 0f 0b e8 f2 76 54 ff 0f 0b 55 41 57 41 56 41
RSP: 0018:ffffc9000432eec0 EFLAGS: 00010293
RAX: ffffffff82370830 RBX: 0000000000000000 RCX: ffff88807d9a9dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000432f028 R08: ffffffff8236fc0c R09: ffffed100eff1db4
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff88801e655d00 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f6fc7dd5700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb7c1906000 CR3: 000000007416c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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