kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 ------------[ cut here ]------------ kernel BUG at mm/filemap.c:859! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 1 UID: 0 PID: 17719 Comm: syz.5.2480 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_add_folio+0x11bc/0x1300 mm/filemap.c:858 Code: 86 c6 ff 4c 89 e7 48 c7 c6 a0 98 b7 8b e8 3c 1f 2a ff 90 0f 0b e8 b4 86 c6 ff 4c 89 e7 48 c7 c6 40 8d b7 8b e8 25 1f 2a ff 90 <0f> 0b e8 9d 86 c6 ff 4c 89 e7 48 c7 c6 a0 98 b7 8b e8 0e 1f 2a ff RSP: 0018:ffffc9000b896e80 EFLAGS: 00010246 RAX: 626cb7c8f9b64a00 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000007 RSI: ffffffff8dcc90a8 RDI: 00000000ffffffff RBP: ffffc9000b897000 R08: ffffffff8fef1a77 R09: 1ffffffff1fde34e R10: dffffc0000000000 R11: fffffbfff1fde34f R12: ffffea0000f5f7c0 R13: dffffc0000000000 R14: ffffea0000f5f7c8 R15: 0000000000000004 FS: 00007f84f5feb6c0(0000) GS:ffff8881257f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555563a71aa8 CR3: 0000000033ac6000 CR4: 0000000000350ef0 Call Trace: filemap_add_folio+0x264/0x530 mm/filemap.c:966 ra_alloc_folio mm/readahead.c:453 [inline] page_cache_ra_order+0x6a8/0xe50 mm/readahead.c:512 do_sync_mmap_readahead+0x6ad/0x8e0 mm/filemap.c:3400 filemap_fault+0x703/0x12e0 mm/filemap.c:3549 __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 32 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 0c d0 79 f5 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000b8978b8 EFLAGS: 00050202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000020000018ebf0 RDX: ffff888030125b80 RSI: 0000000000000002 RDI: 00000000ffffffff RBP: ffffc9000b897a30 R08: ffffc9000b897687 R09: 1ffff92001712ed0 R10: dffffc0000000000 R11: fffff52001712ed1 R12: 1ffff92001712f24 R13: 0000000000000002 R14: 000020000018ebc0 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: 0033:0x7f84f519aeb9 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:00007f84f5feb028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f84f5416090 RCX: 00007f84f519aeb9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007f84f5208c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f84f5416128 R14: 00007f84f5416090 R15: 00007ffec07bcd48 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__filemap_add_folio+0x11bc/0x1300 mm/filemap.c:858 Code: 86 c6 ff 4c 89 e7 48 c7 c6 a0 98 b7 8b e8 3c 1f 2a ff 90 0f 0b e8 b4 86 c6 ff 4c 89 e7 48 c7 c6 40 8d b7 8b e8 25 1f 2a ff 90 <0f> 0b e8 9d 86 c6 ff 4c 89 e7 48 c7 c6 a0 98 b7 8b e8 0e 1f 2a ff RSP: 0018:ffffc9000b896e80 EFLAGS: 00010246 RAX: 626cb7c8f9b64a00 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000007 RSI: ffffffff8dcc90a8 RDI: 00000000ffffffff RBP: ffffc9000b897000 R08: ffffffff8fef1a77 R09: 1ffffffff1fde34e R10: dffffc0000000000 R11: fffffbfff1fde34f R12: ffffea0000f5f7c0 R13: dffffc0000000000 R14: ffffea0000f5f7c8 R15: 0000000000000004 FS: 00007f84f5feb6c0(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555e12ca28 CR3: 0000000033ac6000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 ---------------- 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 32 d0 79 f5 jmp 0xf579d042 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 0c d0 79 f5 jmp 0xf579d042 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