EXT4-fs error (device loop2): ext4_validate_block_bitmap:438: comm syz.2.13535: bg 0: block 112: padding at end of block bitmap is not set
BUG: unable to handle page fault for address: ffffffffffffffec
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 7012067 P4D 7012067 PUD 7014067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 8031 Comm: syz.2.13535 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
RIP: 0010:ext4_free_ext_path fs/ext4/extents.c:128 [inline]
RIP: 0010:ext4_ext_map_blocks+0x2e59/0x6200 fs/ext4/extents.c:4497
Code: 40 01 00 00 4d 85 f6 0f 84 bc 00 00 00 48 89 5c 24 20 49 8d 7e 08 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 38 16 00 00 <41> 0f b7 46 08 c1 e0 04 48 8d 04 40 48 89 44 24 08 49 8d 46 28 48
RSP: 0018:ffffc90005d4ef40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000080000
RDX: ffffc9000547a000 RSI: 000000000000a3ea RDI: ffffffffffffffec
RBP: ffffc90005d4f1f0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000ba9d20 R12: dffffc0000000000
R13: 1ffff92000ba9e14 R14: ffffffffffffffe4 R15: 0000000000000000
FS:  00007f5e3a69c6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffec CR3: 000000011ef8d000 CR4: 00000000003506b0
Call Trace:
 <TASK>
 ext4_map_blocks+0x9d8/0x1b70 fs/ext4/inode.c:679
 mpage_map_one_extent fs/ext4/inode.c:2435 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2488 [inline]
 ext4_writepages+0x1409/0x30e0 fs/ext4/inode.c:2856
 do_writepages+0x3a4/0x5f0 mm/page-writeback.c:2494
 filemap_fdatawrite_wbc+0x128/0x190 mm/filemap.c:408
 __filemap_fdatawrite_range mm/filemap.c:441 [inline]
 file_write_and_wait_range+0x159/0x230 mm/filemap.c:794
 ext4_sync_file+0x1a9/0xa10 fs/ext4/fsync.c:151
 vfs_fsync_range+0x1a1/0x1b0 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2980 [inline]
 ext4_buffered_write_iter+0x573/0x630 fs/ext4/file.c:292
 ext4_file_write_iter+0x191/0x1500 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2282 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x603/0xce0 fs/read_write.c:584
 ksys_pwrite64 fs/read_write.c:699 [inline]
 __do_sys_pwrite64 fs/read_write.c:709 [inline]
 __se_sys_pwrite64 fs/read_write.c:706 [inline]
 __x64_sys_pwrite64+0x197/0x220 fs/read_write.c:706
 x64_sys_call+0x36/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:19
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5e3979ce59
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:00007f5e3a69c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f5e39a16090 RCX: 00007f5e3979ce59
RDX: 000000000000fdef RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007f5e39832d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000e7c R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5e39a16128 R14: 00007f5e39a16090 R15: 00007ffc6d77f628
 </TASK>
Modules linked in:
CR2: ffffffffffffffec
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
RIP: 0010:ext4_free_ext_path fs/ext4/extents.c:128 [inline]
RIP: 0010:ext4_ext_map_blocks+0x2e59/0x6200 fs/ext4/extents.c:4497
Code: 40 01 00 00 4d 85 f6 0f 84 bc 00 00 00 48 89 5c 24 20 49 8d 7e 08 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 38 16 00 00 <41> 0f b7 46 08 c1 e0 04 48 8d 04 40 48 89 44 24 08 49 8d 46 28 48
RSP: 0018:ffffc90005d4ef40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000080000
RDX: ffffc9000547a000 RSI: 000000000000a3ea RDI: ffffffffffffffec
RBP: ffffc90005d4f1f0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000ba9d20 R12: dffffc0000000000
R13: 1ffff92000ba9e14 R14: ffffffffffffffe4 R15: 0000000000000000
FS:  00007f5e3a69c6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffec CR3: 000000011ef8d000 CR4: 00000000003506b0
----------------
Code disassembly (best guess):
   0:	40 01 00             	rex add %eax,(%rax)
   3:	00 4d 85             	add    %cl,-0x7b(%rbp)
   6:	f6 0f 84             	testb  $0x84,(%rdi)
   9:	bc 00 00 00 48       	mov    $0x48000000,%esp
   e:	89 5c 24 20          	mov    %ebx,0x20(%rsp)
  12:	49 8d 7e 08          	lea    0x8(%r14),%rdi
  16:	48 89 f8             	mov    %rdi,%rax
  19:	48 c1 e8 03          	shr    $0x3,%rax
  1d:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
  22:	84 c0                	test   %al,%al
  24:	0f 85 38 16 00 00    	jne    0x1662
* 2a:	41 0f b7 46 08       	movzwl 0x8(%r14),%eax <-- trapping instruction
  2f:	c1 e0 04             	shl    $0x4,%eax
  32:	48 8d 04 40          	lea    (%rax,%rax,2),%rax
  36:	48 89 44 24 08       	mov    %rax,0x8(%rsp)
  3b:	49 8d 46 28          	lea    0x28(%r14),%rax
  3f:	48                   	rex.W