rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2897 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 run_ksoftirqd kernel/softirq.c:1076 [inline] run_ksoftirqd+0x38/0x60 kernel/softirq.c:1068 smpboot_thread_fn+0x3d3/0xaa0 kernel/smpboot.c:160 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ------------[ cut here ]------------ kernel BUG at mm/filemap.c:858! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 1 UID: 0 PID: 13572 Comm: vhost-13566 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__filemap_add_folio+0xfc2/0x12a0 mm/filemap.c:858 Code: 50 c1 ff 48 c7 c6 e0 92 dd 8b 4c 89 ef e8 c6 ea 12 00 90 0f 0b e8 fe 4f c1 ff 48 c7 c6 40 93 dd 8b 4c 89 ef e8 af ea 12 00 90 <0f> 0b e8 e7 4f c1 ff 48 c7 c6 c0 93 dd 8b 4c 89 ef e8 98 ea 12 00 RSP: 0018:ffffc90003bcf3b0 EFLAGS: 00010287 RAX: 00000000000f1b84 RBX: 0000000000112cc0 RCX: ffffc9001a2e2000 RDX: 0000000000100000 RSI: ffffffff825b1ae8 RDI: ffff888075b104c4 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002 R13: ffffea0001cd7840 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fd12a85a6c0(0000) GS:ffff8881241e6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb07204f270 CR3: 0000000052d81000 CR4: 00000000003526f0 Call Trace: filemap_add_folio+0x1d3/0x630 mm/filemap.c:966 ra_alloc_folio mm/readahead.c:470 [inline] page_cache_ra_order+0x602/0xed0 mm/readahead.c:535 do_sync_mmap_readahead mm/filemap.c:3428 [inline] filemap_fault+0x1943/0x3130 mm/filemap.c:3582 __do_fault+0x10b/0x440 mm/memory.c:5425 do_shared_fault mm/memory.c:5924 [inline] do_fault+0x2db/0x1750 mm/memory.c:5998 do_pte_missing mm/memory.c:4566 [inline] handle_pte_fault mm/memory.c:6379 [inline] __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6517 handle_mm_fault+0x37b/0xa30 mm/memory.c:6686 do_user_addr_fault+0x74c/0x12f0 arch/x86/mm/fault.c:1394 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0010:__put_user_2+0xd/0x30 arch/x86/lib/putuser.S:73 Code: 88 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 <66> 89 01 31 c9 0f 01 ca e9 c6 d9 03 00 66 0f 1f 44 00 00 90 90 90 RSP: 0018:ffffc90003bcfb80 EFLAGS: 00050206 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00002000000000c0 RDX: 1ffff1100a7d6994 RSI: ffffffff88fd7295 RDI: ffff888053eb4ca0 RBP: ffff888053eb4bf0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: 00000000ffffffff R14: 0000000000000001 R15: ffff888053eb4d58 vhost_put_used_flags drivers/vhost/vhost.c:1473 [inline] vhost_update_used_flags+0x2f5/0x400 drivers/vhost/vhost.c:2573 vhost_enable_notify+0x34a/0x770 drivers/vhost/vhost.c:3225 vhost_vsock_handle_tx_kick+0x900/0xdc0 drivers/vhost/vsock.c:560 vhost_run_work_list+0x183/0x220 drivers/vhost/vhost.c:454 vhost_task_fn+0x156/0x430 kernel/vhost_task.c:49 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__filemap_add_folio+0xfc2/0x12a0 mm/filemap.c:858 Code: 50 c1 ff 48 c7 c6 e0 92 dd 8b 4c 89 ef e8 c6 ea 12 00 90 0f 0b e8 fe 4f c1 ff 48 c7 c6 40 93 dd 8b 4c 89 ef e8 af ea 12 00 90 <0f> 0b e8 e7 4f c1 ff 48 c7 c6 c0 93 dd 8b 4c 89 ef e8 98 ea 12 00 RSP: 0018:ffffc90003bcf3b0 EFLAGS: 00010287 RAX: 00000000000f1b84 RBX: 0000000000112cc0 RCX: ffffc9001a2e2000 RDX: 0000000000100000 RSI: ffffffff825b1ae8 RDI: ffff888075b104c4 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002 R13: ffffea0001cd7840 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fd12a85a6c0(0000) GS:ffff8881241e6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000030000 CR3: 0000000052d81000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 88 01 mov %al,(%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: 66 89 01 mov %ax,(%rcx) <-- trapping instruction 2d: 31 c9 xor %ecx,%ecx 2f: 0f 01 ca clac 32: e9 c6 d9 03 00 jmp 0x3d9fd 37: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 3d: 90 nop 3e: 90 nop 3f: 90 nop