[BUG] WARNING in simple_rmdir in Linux kernel v6.12

[BUG] WARNING in simple_rmdir in Linux kernel v6.12

[Luka]

Dear Kernel Maintainers,

I am writing to report a potential vulnerability identified in the
upstream Linux Kernel version v6.12, corresponding to the following
commit in the mainline repository:

Git Commit:  adc218676eef25575469234709c2d87185ca223a (tag: v6.12)

This issue was discovered during the testing of the Android 16 AOSP
kernel, which is based on Linux kernel version 6.12, specifically from
the AOSP kernel branch:

AOSP kernel branch: android16-6.12
Manifest path: kernel/common.git
Source URL:  https://android.googlesource.com/kernel/common/+/refs/heads/android16-6.12

Although this kernel branch is used in Android 16 development, its
base is aligned with the upstream Linux v6.12 release. I observed this
issue while conducting stability and fuzzing tests on the Android 16
platform and identified that the root cause lies in the upstream
codebase.


Bug Location: simple_rmdir+0x74/0x168 fs/libfs.c:781

Bug Report: https://hastebin.com/share/akadefefek.css

Entire Log: https://hastebin.com/share/ojebiyetah.perl


Thank you very much for your time and attention. I sincerely apologize
that I am currently unable to provide a reproducer for this issue.
However, I am actively working on reproducing the problem, and I will
make sure to share any findings or reproducing steps with you as soon
as they are available.

I greatly appreciate your efforts in maintaining the Linux kernel and
your attention to this matter.

Best regards,
Luka

Re: [BUG] WARNING in simple_rmdir in Linux kernel v6.12

[Al Viro]

On Wed, Jun 04, 2025 at 12:45:41PM +0800, Luka wrote:
> Dear Kernel Maintainers,

Misbegotten Spamming Turd,

*plonk*