Re: [Bug] possible deadlock in vfs_rmdir in Linux kernel v6.12

[Christian Brauner <brauner@kernel.org>]

Konstantin, this looks actively malicious.
Can we do something about this list-wise?

On Wed, Jun 04, 2025 at 12:38:36PM +0800, Luka wrote:
> 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: vfs_rmdir+0x118/0x488 fs/namei.c:4329
> 
> Bug Report: https://hastebin.com/share/vobatolola.bash
> 
> Entire Log: https://hastebin.com/share/efajodumuh.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

On Wed, Jun 04, 2025 at 12:21:40PM +0800, Luka wrote:
> 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: may_delete+0x72c/0x730 fs/namei.c:3066
> 
> Bug Report: https://hastebin.com/share/amuhawituy.scss
> 
> Entire Log: https://hastebin.com/share/oponarusih.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

On Wed, Jun 04, 2025 at 12:12:26PM +0800, Luka wrote:
> 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: fs_bdev_sync+0x2c/0x68 fs/super.c:1434
> 
> Bug Report: https://hastebin.com/share/pihohaniwi.bash
> 
> Entire Log: https://hastebin.com/share/orufevoquj.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