Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 1 UID: 0 PID: 30344 Comm: syz.5.4904 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:nilfs_mdt_save_to_shadow_map+0x141/0x1c0 fs/nilfs2/mdt.c:559 Code: 3f 4c 8d 63 d8 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 ee a5 84 fe 4d 8b 24 24 49 83 c4 30 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 d0 a5 84 fe 49 8b 34 24 4c 89 ff RSP: 0018:ffffc90004667708 EFLAGS: 00010216 RAX: 0000000000000006 RBX: ffff888058f959b8 RCX: 0000000000000000 RDX: ffff88809e8e0000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff88809e8e0000 R09: 0000000000000003 R10: 0000000000000406 R11: 0000000000000000 R12: 0000000000000030 R13: dffffc0000000000 R14: ffff888083471540 R15: ffff888058f97518 FS: 00007fcebafb46c0(0000) GS:ffff88812555d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcebcc720c0 CR3: 00000000a96ab000 CR4: 0000000000350ef0 Call Trace: nilfs_clean_segments+0x162/0xa50 fs/nilfs2/segment.c:2521 nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:916 [inline] nilfs_ioctl+0x261f/0x2780 fs/nilfs2/ioctl.c:1346 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcebcd9c799 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:00007fcebafb4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcebd016180 RCX: 00007fcebcd9c799 RDX: 0000200000000640 RSI: 0000000040786e88 RDI: 0000000000000004 RBP: 00007fcebce32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcebd016218 R14: 00007fcebd016180 R15: 00007fffe38e15b8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:nilfs_mdt_save_to_shadow_map+0x141/0x1c0 fs/nilfs2/mdt.c:559 Code: 3f 4c 8d 63 d8 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 ee a5 84 fe 4d 8b 24 24 49 83 c4 30 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 d0 a5 84 fe 49 8b 34 24 4c 89 ff RSP: 0018:ffffc90004667708 EFLAGS: 00010216 RAX: 0000000000000006 RBX: ffff888058f959b8 RCX: 0000000000000000 RDX: ffff88809e8e0000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff88809e8e0000 R09: 0000000000000003 R10: 0000000000000406 R11: 0000000000000000 R12: 0000000000000030 R13: dffffc0000000000 R14: ffff888083471540 R15: ffff888058f97518 FS: 00007fcebafb46c0(0000) GS:ffff88812545d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a04182b048 CR3: 00000000a96ab000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 4c 8d 63 d8 lea -0x28(%rbx),%r12 4: 4c 89 e0 mov %r12,%rax 7: 48 c1 e8 03 shr $0x3,%rax b: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) 10: 74 08 je 0x1a 12: 4c 89 e7 mov %r12,%rdi 15: e8 ee a5 84 fe call 0xfe84a608 1a: 4d 8b 24 24 mov (%r12),%r12 1e: 49 83 c4 30 add $0x30,%r12 22: 4c 89 e0 mov %r12,%rax 25: 48 c1 e8 03 shr $0x3,%rax * 29: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 4c 89 e7 mov %r12,%rdi 33: e8 d0 a5 84 fe call 0xfe84a608 38: 49 8b 34 24 mov (%r12),%rsi 3c: 4c 89 ff mov %r15,%rdi