EXT4-fs error (device loop2): ext4_readdir:264: inode #2: block 16: comm syz.2.10: path /1/file1: bad entry in directory: rec_len is smaller than minimal - offset=876, inode=0, rec_len=0, size=1024 fake=0
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WARNING: CPU: 1 PID: 5969 at mm/page-writeback.c:2716 __folio_mark_dirty+0x1fb/0xe20 mm/page-writeback.c:2716
Modules linked in:
CPU: 1 UID: 0 PID: 5969 Comm: syz.2.10 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__folio_mark_dirty+0x1fb/0xe20 mm/page-writeback.c:2716
Code: 3c 38 00 74 08 48 89 df e8 52 a7 26 00 4c 8b 33 4c 89 f6 48 83 e6 08 31 ff e8 d1 ed c4 ff 49 83 e6 08 75 1c e8 66 e8 c4 ff 90 <0f> 0b 90 eb 16 e8 5b e8 c4 ff e9 7e 07 00 00 e8 51 e8 c4 ff eb 05
RSP: 0018:ffffc900056af7b0 EFLAGS: 00010283
RAX: ffffffff81f9c4ea RBX: ffffea0001792340 RCX: 0000000000080000
RDX: ffffc900104c1000 RSI: 0000000000000ab8 RDI: 0000000000000ab9
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff940002f2469 R12: ffff88805d4b8590
R13: ffff88805d4b8588 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f08a035d6c0(0000) GS:ffff888126ef6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f516af54000 CR3: 0000000023fec000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 block_dirty_folio+0x17a/0x1d0 fs/buffer.c:754
 fault_dirty_shared_page+0x103/0x570 mm/memory.c:3519
 wp_page_shared mm/memory.c:3906 [inline]
 do_wp_page+0x263e/0x4930 mm/memory.c:4109
 handle_pte_fault mm/memory.c:6211 [inline]
 __handle_mm_fault mm/memory.c:6336 [inline]
 handle_mm_fault+0x97c/0x3400 mm/memory.c:6505
 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:__put_user_8+0xd/0x20 arch/x86/lib/putuser.S:115
Code: 89 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb <48> 89 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900056afdd8 EFLAGS: 00050202
RAX: 0000000000000400 RBX: 0000000000000000 RCX: 0000200000000338
RDX: 0000000000000001 RSI: ffffffff8cf65609 RDI: ffffffff8b3ddfe0
RBP: ffffc900056afed0 R08: 0000000000000000 R09: ffffffff820942c0
R10: dffffc0000000000 R11: ffffed100b5fc206 R12: 1ffff92000ad5fc0
R13: ffffffffffffffe0 R14: ffff88802fd33403 R15: dffffc0000000000
 __do_sys_getdents fs/readdir.c:333 [inline]
 __se_sys_getdents+0x15b/0x250 fs/readdir.c:312
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f08a211f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f08a035d038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f08a2376090 RCX: 00007f08a211f749
RDX: 0000000000009005 RSI: 0000200000000280 RDI: 0000000000000006
RBP: 00007f08a21a3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f08a2376128 R14: 00007f08a2376090 R15: 00007fff7b223108
 </TASK>
----------------
Code disassembly (best guess):
   0:	89 01                	mov    %eax,(%rcx)
   2:	31 c9                	xor    %ecx,%ecx
   4:	0f 01 ca             	clac
   7:	c3                   	ret
   8:	cc                   	int3
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	48 89 cb             	mov    %rcx,%rbx
  20:	48 c1 fb 3f          	sar    $0x3f,%rbx
  24:	48 09 d9             	or     %rbx,%rcx
  27:	0f 01 cb             	stac
* 2a:	48 89 01             	mov    %rax,(%rcx) <-- trapping instruction
  2d:	31 c9                	xor    %ecx,%ecx
  2f:	0f 01 ca             	clac
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop