Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047] CPU: 1 UID: 0 PID: 11618 Comm: syz.4.1618 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:fd_install+0x57/0x3d0 fs/file.c:685 Code: 48 81 c3 48 09 00 00 48 89 d8 48 c1 e8 03 80 3c 28 00 74 08 48 89 df e8 c7 4c e6 ff 4c 8b 3b 49 8d 5e 40 48 89 d8 48 c1 e8 03 <0f> b6 04 28 84 c0 0f 85 29 03 00 00 8b 1b 89 de 81 e6 00 00 00 01 RSP: 0018:ffffc9000e647c40 EFLAGS: 00010202 RAX: 0000000000000008 RBX: 0000000000000041 RCX: 0000000000080000 RDX: ffffc9000cbad000 RSI: 00000000000000f3 RDI: 00000000000000f4 RBP: dffffc0000000000 R08: ffff88807e9b0523 R09: 1ffff1100fd360a4 R10: dffffc0000000000 R11: ffffed100fd360a5 R12: 0000000000000003 R13: 0000000000000003 R14: 0000000000000001 R15: ffff8880258b30c0 FS: 0000000000000000(0000) GS:ffff8881261c5000(0063) knlGS:00000000f54bdb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f7456288 CR3: 00000000769d0000 CR4: 00000000003526f0 Call Trace: do_mq_open+0x5a0/0x770 ipc/mqueue.c:932 __do_compat_sys_mq_open ipc/mqueue.c:1515 [inline] __se_compat_sys_mq_open ipc/mqueue.c:1505 [inline] __ia32_compat_sys_mq_open+0x1f9/0x250 ipc/mqueue.c:1505 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf70cd539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f54bd55c EFLAGS: 00000206 ORIG_RAX: 0000000000000115 RAX: ffffffffffffffda RBX: 0000000080000000 RCX: 00000000000008c2 RDX: 00000000000000b3 RSI: 0000000080000080 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:fd_install+0x57/0x3d0 fs/file.c:685 Code: 48 81 c3 48 09 00 00 48 89 d8 48 c1 e8 03 80 3c 28 00 74 08 48 89 df e8 c7 4c e6 ff 4c 8b 3b 49 8d 5e 40 48 89 d8 48 c1 e8 03 <0f> b6 04 28 84 c0 0f 85 29 03 00 00 8b 1b 89 de 81 e6 00 00 00 01 RSP: 0018:ffffc9000e647c40 EFLAGS: 00010202 RAX: 0000000000000008 RBX: 0000000000000041 RCX: 0000000000080000 RDX: ffffc9000cbad000 RSI: 00000000000000f3 RDI: 00000000000000f4 RBP: dffffc0000000000 R08: ffff88807e9b0523 R09: 1ffff1100fd360a4 R10: dffffc0000000000 R11: ffffed100fd360a5 R12: 0000000000000003 R13: 0000000000000003 R14: 0000000000000001 R15: ffff8880258b30c0 FS: 0000000000000000(0000) GS:ffff8881261c5000(0063) knlGS:00000000f54bdb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000080108018 CR3: 00000000769d0000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffeff7ff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 48 81 c3 48 09 00 00 add $0x948,%rbx 7: 48 89 d8 mov %rbx,%rax a: 48 c1 e8 03 shr $0x3,%rax e: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) 12: 74 08 je 0x1c 14: 48 89 df mov %rbx,%rdi 17: e8 c7 4c e6 ff call 0xffe64ce3 1c: 4c 8b 3b mov (%rbx),%r15 1f: 49 8d 5e 40 lea 0x40(%r14),%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 0f b6 04 28 movzbl (%rax,%rbp,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 29 03 00 00 jne 0x35f 36: 8b 1b mov (%rbx),%ebx 38: 89 de mov %ebx,%esi 3a: 81 e6 00 00 00 01 and $0x1000000,%esi