syzbot

 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
------------[ cut here ]------------
kernel BUG at mm/filemap.c:3579!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 16866 Comm: syz.8.2844 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:filemap_fault+0x125b/0x12e0 mm/filemap.c:3579
Code: 38 c1 0f 8c 79 fd ff ff 4c 89 ff e8 cf d3 2d 00 e9 6c fd ff ff e8 25 84 c5 ff 48 89 df 48 c7 c6 a0 8f b7 8b e8 96 1c 29 ff 90 <0f> 0b e8 0e 84 c5 ff 48 8b 3c 24 48 c7 c6 20 98 b7 8b e8 7e 1c 29
RSP: 0018:ffffc9000da97280 EFLAGS: 00010246
RAX: 767bce901c4acc00 RBX: ffffea00022b1f00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8dcc95fc RDI: 00000000ffffffff
RBP: ffffc9000da973c0 R08: ffffffff8fef1b77 R09: 1ffffffff1fde36e
R10: dffffc0000000000 R11: fffffbfff1fde36f R12: ffffea00022b1f08
R13: 1ffffd40004563e1 R14: ffffea00022b1f18 R15: dffffc0000000000
FS:  00007fc4af8246c0(0000) GS:ffff8881257f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000208030 CR3: 0000000086ccd000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 __do_fault+0x138/0x390 mm/memory.c:5323
 do_shared_fault mm/memory.c:5822 [inline]
 do_fault mm/memory.c:5896 [inline]
 do_pte_missing+0x5a4/0x37a0 mm/memory.c:4404
 handle_pte_fault mm/memory.c:6276 [inline]
 __handle_mm_fault mm/memory.c:6414 [inline]
 handle_mm_fault+0x1b8c/0x32a0 mm/memory.c:6583
 do_user_addr_fault+0x75b/0x1360 arch/x86/mm/fault.c:1385
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 62 d0 79 f5 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca e9 3c d0 79 f5 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000da978b8 EFLAGS: 00050202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000020000007e170
RDX: ffff888020e9db80 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc9000da97a30 R08: ffffc9000da97687 R09: 1ffff92001b52ed0
R10: dffffc0000000000 R11: fffff52001b52ed1 R12: 1ffff92001b52f24
R13: 0000000000000002 R14: 000020000007e140 R15: dffffc0000000000
 ____sys_recvmsg+0x2be/0x4a0 net/socket.c:2825
 ___sys_recvmsg+0x215/0x590 net/socket.c:2854
 do_recvmmsg+0x334/0x800 net/socket.c:2949
 __sys_recvmmsg net/socket.c:3023 [inline]
 __do_sys_recvmmsg net/socket.c:3046 [inline]
 __se_sys_recvmmsg net/socket.c:3039 [inline]
 __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3039
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc4ae99aeb9
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:00007fc4af824028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fc4aec16090 RCX: 00007fc4ae99aeb9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007fc4aea08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc4aec16128 R14: 00007fc4aec16090 R15: 00007ffdee239db8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:filemap_fault+0x125b/0x12e0 mm/filemap.c:3579
Code: 38 c1 0f 8c 79 fd ff ff 4c 89 ff e8 cf d3 2d 00 e9 6c fd ff ff e8 25 84 c5 ff 48 89 df 48 c7 c6 a0 8f b7 8b e8 96 1c 29 ff 90 <0f> 0b e8 0e 84 c5 ff 48 8b 3c 24 48 c7 c6 20 98 b7 8b e8 7e 1c 29
RSP: 0018:ffffc9000da97280 EFLAGS: 00010246
RAX: 767bce901c4acc00 RBX: ffffea00022b1f00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8dcc95fc RDI: 00000000ffffffff
RBP: ffffc9000da973c0 R08: ffffffff8fef1b77 R09: 1ffffffff1fde36e
R10: dffffc0000000000 R11: fffffbfff1fde36f R12: ffffea00022b1f08
R13: 1ffffd40004563e1 R14: ffffea00022b1f18 R15: dffffc0000000000
FS:  00007fc4af8246c0(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f976bde1198 CR3: 0000000086ccd000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	d9 0f                	(bad) (%rdi)
   2:	01 cb                	add    %ecx,%ebx
   4:	89 01                	mov    %eax,(%rcx)
   6:	31 c9                	xor    %ecx,%ecx
   8:	0f 01 ca             	clac
   b:	e9 62 d0 79 f5       	jmp    0xf579d072
  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:	90                   	nop
  1e:	90                   	nop
  1f:	90                   	nop
  20:	90                   	nop
  21:	90                   	nop
  22:	90                   	nop
  23:	90                   	nop
  24:	90                   	nop
  25:	90                   	nop
  26:	90                   	nop
  27:	0f 01 cb             	stac
* 2a:	89 01                	mov    %eax,(%rcx) <-- trapping instruction
  2c:	31 c9                	xor    %ecx,%ecx
  2e:	0f 01 ca             	clac
  31:	e9 3c d0 79 f5       	jmp    0xf579d072
  36:	90                   	nop
  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