Re: [BUG] general protection fault in security_path_post_mknod

[Paul Moore]

On Fri, Aug 28, 2026 at 2:11 AM Farhad Alemi <farhad.alemi@xxxxxxxxxxxx> wrote:
>
> Hello,
>
> As part of the kernel research at ASU's SEFCOM
> lab, we hit the crash below. Crash reports can be found here:
>
>   https://github.com/farhad-alemi/public_bug_reports/tree/main/178-general-protection-fault-in-security-path-post-mknod/
>
>   Oops: general protection fault, probably for non-canonical address
> 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
>   KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
>   RIP: 0010:security_path_post_mknod+0x49/0x1e0 security/security.c:1430
>   Call Trace:
>    security_path_post_mknod+0x49/0x1e0 security/security.c:1430
>    filename_mknodat+0x40e/0x660 fs/namei.c:5172
>    __do_sys_mknod fs/namei.c:5207 [inline]
>    __se_sys_mknod+0x3a/0x150 fs/namei.c:5204
>    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>    do_syscall_64+0x146/0x480 arch/x86/entry/syscall_64.c:94
>    entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Our reproducer.c is available upon request.
>
> Happy to test a patch if that would help.

Hi Farhad, thanks for the report.  Do you think you can diagnose the
problem and submit a patch?  Bug reports are always welcome, but as
you may have noticed, we have plenty of those at the moment.  People
willing to not only identify problems but fix them too is something we
are running a bit short on at the moment ;)

-- 
paul-moore.com