general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 1 PID: 4151 Comm: syz.1.1141 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:f2fs_test_and_set_bit fs/f2fs/f2fs.h:3004 [inline] RIP: 0010:update_sit_entry_for_alloc fs/f2fs/segment.c:2399 [inline] RIP: 0010:update_sit_entry+0x508/0x15c0 fs/f2fs/segment.c:2443 Code: 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 1f 9d 8a 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 6d 0f 00 00 44 0f b6 23 44 89 e0 44 08 f8 RSP: 0018:ffffc9000ffc7160 EFLAGS: 00010206 RAX: 0000000000000006 RBX: 0000000000000032 RCX: dffffc0000000000 RDX: ffff88811f9bbcc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000ffc7230 R08: ffff88811f9bbcc0 R09: 0000000000000003 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000000 R13: ffff88810d2000d8 R14: 0000000000000032 R15: 0000000000000010 FS: 00007f1672e476c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1672e04ff8 CR3: 000000012991f000 CR4: 00000000003506a0 Call Trace: f2fs_allocate_data_block+0x14ca/0x3b30 fs/f2fs/segment.c:3434 __allocate_data_block fs/f2fs/data.c:1498 [inline] f2fs_map_blocks+0x1712/0x3c60 fs/f2fs/data.c:1687 f2fs_expand_inode_data+0x631/0xa60 fs/f2fs/file.c:1860 f2fs_fallocate+0x3cf/0x730 fs/f2fs/file.c:1961 vfs_fallocate+0x4c5/0x5a0 fs/open.c:324 ioctl_preallocate fs/ioctl.c:290 [inline] file_ioctl fs/ioctl.c:330 [inline] do_vfs_ioctl+0x194b/0x1cd0 fs/ioctl.c:849 __do_sys_ioctl fs/ioctl.c:868 [inline] __se_sys_ioctl+0x9f/0x1b0 fs/ioctl.c:856 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856 x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17 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: 0033:0x7f1671f9c819 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:00007f1672e47028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1672215fa0 RCX: 00007f1671f9c819 RDX: 0000200000000040 RSI: 0000000040305828 RDI: 0000000000000004 RBP: 00007f1672032c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1672216038 R14: 00007f1672215fa0 R15: 00007ffdffa53228 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:f2fs_test_and_set_bit fs/f2fs/f2fs.h:3004 [inline] RIP: 0010:update_sit_entry_for_alloc fs/f2fs/segment.c:2399 [inline] RIP: 0010:update_sit_entry+0x508/0x15c0 fs/f2fs/segment.c:2443 Code: 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 1f 9d 8a 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 6d 0f 00 00 44 0f b6 23 44 89 e0 44 08 f8 RSP: 0018:ffffc9000ffc7160 EFLAGS: 00010206 RAX: 0000000000000006 RBX: 0000000000000032 RCX: dffffc0000000000 RDX: ffff88811f9bbcc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000ffc7230 R08: ffff88811f9bbcc0 R09: 0000000000000003 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000000 R13: ffff88810d2000d8 R14: 0000000000000032 R15: 0000000000000010 FS: 00007f1672e476c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8511748060 CR3: 000000012991f000 CR4: 00000000003506b0 ---------------- 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 1f 9d 8a ff call 0xff8a9d2d 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 6d 0f 00 00 jne 0xf9e 31: 44 0f b6 23 movzbl (%rbx),%r12d 35: 44 89 e0 mov %r12d,%eax 38: 44 08 f8 or %r15b,%al