Audit system development
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From: Paul Moore <paul@paul-moore.com>
To: Ricardo Robaina <rrobaina@redhat.com>,
	audit@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: eparis@redhat.com, rgb@redhat.com, longman@redhat.com,
	Ricardo Robaina <rrobaina@redhat.com>
Subject: Re: [PATCH 2/2] audit: fix removal of dangling executable rules
Date: Tue, 12 May 2026 15:12:34 -0400	[thread overview]
Message-ID: <402f11211fcab76b6410f3f57372c58f@paul-moore.com> (raw)
In-Reply-To: <c5fd6163fd285fca25460ce821f95b15383f920a.1776176104.git.rrobaina@redhat.com>

On Apr 14, 2026 Ricardo Robaina <rrobaina@redhat.com> wrote:
> 
> When an audited executable is deleted from the disk, its dentry
> becomes negative. Any later attempt to delete the associated audit
> rule will lead to audit_alloc_mark() encountering this negative
> dentry and immediately aborting, returning -ENOENT.
> 
> This early abort prevents the subsystem from allocating the temporary
> fsnotify mark needed to construct the search key, meaning the kernel
> cannot find the existing rule in its own lists to delete it. This
> leaves a dangling rule in memory, resulting in the following error
> while attempting to delete the rule:
> 
>  # ./audit-dupe-exe-deadlock.sh
>  No rules
>  Error deleting rule (No such file or directory)
>  There was an error while processing parameters
> 
>  # auditctl -l
>  -a always,exit -S all -F exe=/tmp/file -F path=/tmp/file -F key=dr
> 
>  # auditctl -D
>  Error deleting rule (No such file or directory)
>  There was an error while processing parameters
> 
> This patch fixes this issue by removing the d_really_is_negative()
> check. By doing so, a dummy mark can be successfully generated for
> the deleted path, which allows the audit subsystem to properly match
> and flush the dangling rule.
> 
> Fixes: 76a53de6f7ff ("VFS/audit: introduce kern_path_parent() for audit")
> Acked-by: Waiman Long <longman@redhat.com>
> Signed-off-by: Ricardo Robaina <rrobaina@redhat.com>
> Acked-by: Richard Guy Briggs <rgb@redhat.com>
> ---
>  kernel/audit_fsnotify.c | 4 ----
>  1 file changed, 4 deletions(-)

Good catch.  I might reorder the patchset so this patch comes first
in the patchset, but this isn't a big deal either way.

--
paul-moore.com

  parent reply	other threads:[~2026-05-12 19:12 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-14 20:00 [PATCH 0/2] audit: fix recursive locking deadlock and dangling rule removal Ricardo Robaina
2026-04-14 20:00 ` [PATCH 1/2] audit: fix recursive locking deadlock in audit_dupe_exe() Ricardo Robaina
2026-04-15 18:21   ` Richard Guy Briggs
2026-05-12 19:12   ` Paul Moore
2026-05-13 21:02     ` Ricardo Robaina
2026-04-14 20:00 ` [PATCH 2/2] audit: fix removal of dangling executable rules Ricardo Robaina
2026-04-15 18:22   ` Richard Guy Briggs
2026-05-12 19:12   ` Paul Moore [this message]
2026-05-13 21:04     ` Ricardo Robaina

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