F2FS-fs (loop2): Found nat_bits in checkpoint F2FS-fs (loop2): Start checkpoint disabled! F2FS-fs (loop2): f2fs_disable_checkpoint() finish, err:0 F2FS-fs (loop2): Mounted with checkpoint version = 48b305e6 general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 0 PID: 480 Comm: syz.2.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:f2fs_test_and_set_bit fs/f2fs/f2fs.h:2954 [inline] RIP: 0010:update_sit_entry_for_alloc fs/f2fs/segment.c:2398 [inline] RIP: 0010:update_sit_entry+0x4f9/0x15a0 fs/f2fs/segment.c:2442 Code: 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 9e 07 8b ff 48 8b 1b 4c 01 f3 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 55 0f 00 00 44 0f b6 23 44 89 e0 44 08 f8 RSP: 0018:ffffc90000c46500 EFLAGS: 00010206 RAX: 0000000000000005 RBX: 000000000000002b RCX: dffffc0000000000 RDX: ffff888112aa2880 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000c465d0 R08: ffff888112aa2880 R09: 0000000000000003 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000000 R13: ffff8881144e80c8 R14: 000000000000002b R15: 0000000000000020 FS: 00007f4547c236c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30b5ffff CR3: 000000012d4fd000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: f2fs_allocate_data_block+0x14b8/0x3b00 fs/f2fs/segment.c:3432 do_write_page+0x2c5/0xc60 fs/f2fs/segment.c:3534 f2fs_outplace_write_data+0x14f/0x2d0 fs/f2fs/segment.c:3607 f2fs_do_write_data_page+0x105d/0x14b0 fs/f2fs/data.c:2797 f2fs_write_single_data_page+0x944/0x1810 fs/f2fs/data.c:2914 f2fs_write_cache_pages fs/f2fs/data.c:3166 [inline] __f2fs_write_data_pages fs/f2fs/data.c:3316 [inline] f2fs_write_data_pages+0x1406/0x28d0 fs/f2fs/data.c:3343 do_writepages+0x3a4/0x5f0 mm/page-writeback.c:2494 filemap_fdatawrite_wbc+0x128/0x190 mm/filemap.c:408 __filemap_fdatawrite_range mm/filemap.c:441 [inline] filemap_write_and_wait_range+0x131/0x210 mm/filemap.c:694 f2fs_flush_buffered_write fs/f2fs/file.c:4763 [inline] f2fs_file_write_iter+0x795/0x2610 fs/f2fs/file.c:4977 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x665/0xb40 fs/read_write.c:861 vfs_iter_write+0x7d/0xa0 fs/read_write.c:902 iter_file_splice_write+0x69e/0xcd0 fs/splice.c:685 do_splice_from fs/splice.c:763 [inline] direct_splice_actor+0xf7/0x130 fs/splice.c:930 splice_direct_to_actor+0x4ad/0xb30 fs/splice.c:885 do_splice_direct+0x1c2/0x2d0 fs/splice.c:973 do_sendfile+0x5ed/0xea0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x199/0x1f0 fs/read_write.c:1309 x64_sys_call+0x62c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:41 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4546d99079 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:00007f4547c23028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f4546fc5fa0 RCX: 00007f4546d99079 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005 RBP: 00007f4546e2ba4c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000fffe80 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4546fc5fa0 R15: 00007ffe50729698 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:f2fs_test_and_set_bit fs/f2fs/f2fs.h:2954 [inline] RIP: 0010:update_sit_entry_for_alloc fs/f2fs/segment.c:2398 [inline] RIP: 0010:update_sit_entry+0x4f9/0x15a0 fs/f2fs/segment.c:2442 Code: 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 9e 07 8b ff 48 8b 1b 4c 01 f3 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 55 0f 00 00 44 0f b6 23 44 89 e0 44 08 f8 RSP: 0018:ffffc90000c46500 EFLAGS: 00010206 RAX: 0000000000000005 RBX: 000000000000002b RCX: dffffc0000000000 RDX: ffff888112aa2880 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000c465d0 R08: ffff888112aa2880 R09: 0000000000000003 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000000 R13: ffff8881144e80c8 R14: 000000000000002b R15: 0000000000000020 FS: 00007f4547c236c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4546de67c0 CR3: 000000012d4fd000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 5 bytes skipped: 0: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) 4: 74 08 je 0xe 6: 48 89 df mov %rbx,%rdi 9: e8 9e 07 8b ff call 0xff8b07ac e: 48 8b 1b mov (%rbx),%rbx 11: 4c 01 f3 add %r14,%rbx 14: 48 89 d8 mov %rbx,%rax 17: 48 c1 e8 03 shr $0x3,%rax 1b: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 22: fc ff df * 25: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax <-- trapping instruction 29: 84 c0 test %al,%al 2b: 0f 85 55 0f 00 00 jne 0xf86 31: 44 0f b6 23 movzbl (%rbx),%r12d 35: 44 89 e0 mov %r12d,%eax 38: 44 08 f8 or %r15b,%al