Re: [PATCH 2/2] audit: fix removal of dangling executable rules
From: Ricardo Robaina
Date: Wed May 13 2026 - 17:09:14 EST
On Tue, May 12, 2026 at 4:12 PM Paul Moore <paul@xxxxxxxxxxxxxx> wrote:
>
> On Apr 14, 2026 Ricardo Robaina <rrobaina@xxxxxxxxxx> 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@xxxxxxxxxx>
> > Signed-off-by: Ricardo Robaina <rrobaina@xxxxxxxxxx>
> > Acked-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > ---
> > 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
>
I'm sending the v2 reordered. Thanks for reviewing it as well!