------------[ cut here ]------------ WARNING: mm/page-writeback.c:2710 at __folio_mark_dirty+0x202/0xe10 mm/page-writeback.c:2710, CPU#1: syz.4.1105/11523 Modules linked in: CPU: 1 UID: 0 PID: 11523 Comm: syz.4.1105 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__folio_mark_dirty+0x202/0xe10 mm/page-writeback.c:2710 Code: 3c 20 00 74 08 48 89 df e8 cb f7 2a 00 4c 8b 33 4c 89 f6 48 83 e6 08 31 ff e8 1a 54 c4 ff 49 83 e6 08 75 20 e8 2f 4f c4 ff 90 <0f> 0b 90 eb 1a e8 24 4f c4 ff 48 8b 2c 24 e9 5d 07 00 00 e8 16 4f RSP: 0018:ffffc90002f47348 EFLAGS: 00010046 RAX: ffffffff81fd6931 RBX: ffffea0001a51f00 RCX: 0000000000080000 RDX: ffffc9000d011000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffff8880573bdb58 R08: ffffea0001a51f07 R09: 1ffffd400034a3e0 R10: dffffc0000000000 R11: fffff9400034a3e1 R12: dffffc0000000000 R13: ffff8880573bdb60 R14: 0000000000000000 R15: 0000000000000001 FS: 00007fd5a7aec6c0(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000008c CR3: 0000000067ba4000 CR4: 00000000003526f0 Call Trace: block_dirty_folio+0x17a/0x1d0 fs/buffer.c:754 fault_dirty_shared_page+0x103/0x550 mm/memory.c:3558 wp_page_shared mm/memory.c:3945 [inline] do_wp_page+0x26a9/0x5750 mm/memory.c:4148 handle_pte_fault mm/memory.c:6289 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0x14c5/0x32b0 mm/memory.c:6580 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:rep_movs_alternative+0x11/0x90 arch/x86/lib/copy_user_64.S:47 Code: e9 c4 48 04 00 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 83 f9 40 73 44 83 f9 08 73 25 85 c9 74 0f 8a 06 <88> 07 48 ff c7 48 ff c6 48 ff c9 75 f1 e9 8d 48 04 00 66 2e 0f 1f RSP: 0018:ffffc90002f479e8 EFLAGS: 00050202 RAX: ffffffff848fcb14 RBX: 0000000000000004 RCX: 0000000000000004 RDX: 0000000000000000 RSI: ffffc90002f47aa0 RDI: 000020000000008c RBP: ffffc90002f47b40 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520005e8f54 R12: 0000200000000090 R13: 00007ffffffff000 R14: ffffc90002f47aa0 R15: 000020000000008c copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] _inline_copy_to_user include/linux/uaccess.h:206 [inline] _copy_to_user+0x8a/0xb0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:236 [inline] bpf_test_finish+0x1dd/0x6d0 net/bpf/test_run.c:491 bpf_prog_test_run_xdp+0x891/0x10e0 net/bpf/test_run.c:1400 bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4704 __sys_bpf+0x5ee/0x8a0 kernel/bpf/syscall.c:6226 __do_sys_bpf kernel/bpf/syscall.c:6321 [inline] __se_sys_bpf kernel/bpf/syscall.c:6319 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6319 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd5a6b8f749 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:00007fd5a7aec038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fd5a6de5fa0 RCX: 00007fd5a6b8f749 RDX: 0000000000000050 RSI: 0000200000000080 RDI: 000000000000000a RBP: 00007fd5a6c13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd5a6de6038 R14: 00007fd5a6de5fa0 R15: 00007ffc49bfca18 ---------------- Code disassembly (best guess): 0: e9 c4 48 04 00 jmp 0x448c9 5: cc int3 6: cc int3 7: cc int3 8: cc int3 9: 90 nop a: 90 nop b: 90 nop 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: 48 83 f9 40 cmp $0x40,%rcx 1d: 73 44 jae 0x63 1f: 83 f9 08 cmp $0x8,%ecx 22: 73 25 jae 0x49 24: 85 c9 test %ecx,%ecx 26: 74 0f je 0x37 28: 8a 06 mov (%rsi),%al * 2a: 88 07 mov %al,(%rdi) <-- trapping instruction 2c: 48 ff c7 inc %rdi 2f: 48 ff c6 inc %rsi 32: 48 ff c9 dec %rcx 35: 75 f1 jne 0x28 37: e9 8d 48 04 00 jmp 0x448c9 3c: 66 data16 3d: 2e cs 3e: 0f .byte 0xf 3f: 1f (bad)