syzbot
kernel BUG in ext4_ext_insert_index
Status:
upstream: reported C repro on 2025/05/12 05:54
Reported-by: syzbot+fbce9d1fb2a8d5af8fa7@syzkaller.appspotmail.com
First crash: 468d, last: 48d
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Last patch testing requests (10)
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Fix bisection attempts (3)
Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/ext4/extents.c:1014!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 282 Comm: syz-executor155 Not tainted 5.10.238-syzkaller-00282-gd76d4cd0623a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:ext4_ext_insert_index+0x52d/0x530 fs/ext4/extents.c:1014
Code: 4c 89 fa e9 ca fd ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c dd fd ff ff 4c 89 f7 e8 ad a2 d3 ff e9 d0 fd ff ff e8 83 b2 99 ff <0f> 0b 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 81 ec c0 00 00
RSP: 0018:ffffc90000b26b20 EFLAGS: 00010293
RAX: ffffffff81c9e18d RBX: ffff888120a18424 RCX: ffff88811d443b40
RDX: 0000000000000000 RSI: 00000000fffffffe RDI: 0000000000000000
RBP: ffffc90000b26b90 R08: dffffc0000000000 R09: ffffed1024282b3c
R10: ffffed1024282b3c R11: 1ffff11024282b3b R12: 0000000000000000
R13: 00000000000000cb R14: 00000000fffffffe R15: 0000000000000054
FS: 0000555592d56380(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000002c0bf CR3: 000000011daa7000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ext4_ext_split fs/ext4/extents.c:1272 [inline]
ext4_ext_create_new_leaf fs/ext4/extents.c:1414 [inline]
ext4_ext_insert_extent+0x38c3/0x4530 fs/ext4/extents.c:2097
ext4_ext_map_blocks+0x148c/0x5d40 fs/ext4/extents.c:4354
ext4_map_blocks+0x978/0x1bc0 fs/ext4/inode.c:674
_ext4_get_block+0x1bb/0x4b0 fs/ext4/inode.c:817
ext4_get_block_unwritten+0x2a/0x40 fs/ext4/inode.c:848
ext4_block_write_begin+0x567/0x1330 fs/ext4/inode.c:1101
ext4_write_begin+0x651/0x1550 fs/ext4/ext4_jbd2.h:-1
ext4_da_write_begin+0x455/0xe80 fs/ext4/inode.c:3033
generic_perform_write+0x2be/0x510 mm/filemap.c:3509
ext4_buffered_write_iter+0x4b8/0x640 fs/ext4/file.c:271
ext4_file_write_iter+0x536/0x1980 fs/ext4/file.c:-1
call_write_iter include/linux/fs.h:2058 [inline]
new_sync_write fs/read_write.c:518 [inline]
vfs_write+0x725/0xd60 fs/read_write.c:605
ksys_pwrite64 fs/read_write.c:712 [inline]
__do_sys_pwrite64 fs/read_write.c:722 [inline]
__se_sys_pwrite64 fs/read_write.c:719 [inline]
__x64_sys_pwrite64+0x191/0x220 fs/read_write.c:719
do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f2340a2cbf9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 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:00007ffc758e7ed8 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 0031656c69662f2e RCX: 00007f2340a2cbf9
RDX: 00000000200000c1 RSI: 00002000000000c0 RDI: 0000000000000006
RBP: 0000200000000040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000009000 R11: 0000000000000246 R12: 0031656c69662f2e
R13: 5f646165726f6964 R14: 65726f6e67693d72 R15: 00007f2340a7505e
Modules linked in:
---[ end trace 52dd77d2decb3d46 ]---
RIP: 0010:ext4_ext_insert_index+0x52d/0x530 fs/ext4/extents.c:1014
Code: 4c 89 fa e9 ca fd ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c dd fd ff ff 4c 89 f7 e8 ad a2 d3 ff e9 d0 fd ff ff e8 83 b2 99 ff <0f> 0b 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 81 ec c0 00 00
RSP: 0018:ffffc90000b26b20 EFLAGS: 00010293
RAX: ffffffff81c9e18d RBX: ffff888120a18424 RCX: ffff88811d443b40
RDX: 0000000000000000 RSI: 00000000fffffffe RDI: 0000000000000000
RBP: ffffc90000b26b90 R08: dffffc0000000000 R09: ffffed1024282b3c
R10: ffffed1024282b3c R11: 1ffff11024282b3b R12: 0000000000000000
R13: 00000000000000cb R14: 00000000fffffffe R15: 0000000000000054
FS: 0000555592d56380(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000002c0bf CR3: 000000011daa7000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
* Struck through repros no longer work on HEAD.