syzbot

kernel BUG at fs/ext4/extents.c:2135!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 511 Comm: syz.3.30 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:ext4_ext_insert_extent+0x4592/0x45d0 fs/ext4/extents.c:2135
Code: ff ff 89 d9 80 e1 07 fe c1 38 c1 0f 8c 08 e9 ff ff 48 89 df e8 4f 51 d4 ff e9 fb e8 ff ff e8 55 d0 99 ff 0f 0b e8 4e d0 99 ff <0f> 0b e8 47 d0 99 ff 0f 0b 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 30
RSP: 0018:ffffc90002d76340 EFLAGS: 00010293
RAX: ffffffff81cae602 RBX: ffff88812f7e9400 RCX: ffff8881188ba780
RDX: 0000000000000000 RSI: 0000000000000045 RDI: 0000000000000045
RBP: ffffc90002d764f0 R08: ffff888110695d27 R09: 1ffff110220d2ba4
R10: dffffc0000000000 R11: ffffed10220d2ba5 R12: 0000000000000045
R13: 1ffff11023252a08 R14: ffff88812f7e9490 R15: 0000000000000045
FS:  00007f4c05a586c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6be4897e80 CR3: 0000000112b12000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ext4_split_extent_at+0x79b/0xe90 fs/ext4/extents.c:3230
 ext4_split_extent+0x1ba/0x4c0 fs/ext4/extents.c:3349
 ext4_split_convert_extents fs/ext4/extents.c:3709 [inline]
 ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3870 [inline]
 ext4_ext_map_blocks+0x1084/0x5dd0 fs/ext4/extents.c:4225
 ext4_map_blocks+0x985/0x1bd0 fs/ext4/inode.c:674
 _ext4_get_block+0x1d1/0x4e0 fs/ext4/inode.c:817
 ext4_get_block_unwritten+0x2a/0x40 fs/ext4/inode.c:848
 ext4_block_write_begin+0x573/0x1340 fs/ext4/inode.c:1101
 ext4_write_begin+0x67e/0x1690 fs/ext4/ext4_jbd2.h:-1
 ext4_da_write_begin+0x478/0xf10 fs/ext4/inode.c:3033
 generic_perform_write+0x2ce/0x540 mm/filemap.c:3509
 ext4_buffered_write_iter+0x4b8/0x640 fs/ext4/file.c:271
 ext4_file_write_iter+0x53f/0x1980 fs/ext4/file.c:-1
 do_iter_readv_writev+0x478/0x5f0 fs/read_write.c:-1
 do_iter_write+0x189/0x630 fs/read_write.c:866
 vfs_iter_write+0x7d/0xa0 fs/read_write.c:907
 iter_file_splice_write+0x68c/0xcb0 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0xe9/0x120 fs/splice.c:936
 splice_direct_to_actor+0x4cb/0xb30 fs/splice.c:891
 do_splice_direct+0x1c2/0x2d0 fs/splice.c:979
 do_sendfile+0x8df/0x1040 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0x199/0x1f0 fs/read_write.c:1304
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f4c05c16799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4c05a58028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f4c05e90090 RCX: 00007f4c05c16799
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 00007f4c05cacbd9 R08: 0000000000000000 R09: 0000000000000000
R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4c05e90128 R14: 00007f4c05e90090 R15: 00007fffe6f18f38
Modules linked in:
---[ end trace 748038e09747d123 ]---
RIP: 0010:ext4_ext_insert_extent+0x4592/0x45d0 fs/ext4/extents.c:2135
Code: ff ff 89 d9 80 e1 07 fe c1 38 c1 0f 8c 08 e9 ff ff 48 89 df e8 4f 51 d4 ff e9 fb e8 ff ff e8 55 d0 99 ff 0f 0b e8 4e d0 99 ff <0f> 0b e8 47 d0 99 ff 0f 0b 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 30
RSP: 0018:ffffc90002d76340 EFLAGS: 00010293
RAX: ffffffff81cae602 RBX: ffff88812f7e9400 RCX: ffff8881188ba780
RDX: 0000000000000000 RSI: 0000000000000045 RDI: 0000000000000045
RBP: ffffc90002d764f0 R08: ffff888110695d27 R09: 1ffff110220d2ba4
R10: dffffc0000000000 R11: ffffed10220d2ba5 R12: 0000000000000045
R13: 1ffff11023252a08 R14: ffff88812f7e9490 R15: 0000000000000045
FS:  00007f4c05a586c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000300bf CR3: 0000000112b12000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400