apparmor: delete the dentry in aafs_remove() to avoid a leak

BugLink: https://bugs.launchpad.net/bugs/1855787
[ Upstream commit 201218e4d3dfa1346e30997f48725acce3f26d01 ]

Although the apparmorfs dentries are always dropped from the dentry cache
when the usage count drops to zero, there is no guarantee that this will
happen in aafs_remove(), as another thread might still be using it. In
this scenario, this means that the dentry will temporarily continue to
appear in the results of lookups, even after the call to aafs_remove().

In the case of removal of a profile - it also causes simple_rmdir()
on the profile directory to fail, as the directory won't be empty until
the usage counts of all child dentries have decreased to zero. This
results in the dentry for the profile directory leaking and appearing
empty in the file system tree forever.

Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 5386fe3bf88c847f1529a52dcd898b528dd4512d..d48fc4fdee3c98261d45e203e4f482e6c8c3ff56 100644 (file)
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -364,6 +364,7 @@ static void aafs_remove(struct dentry *dentry)
                        simple_rmdir(dir, dentry);
                else
                        simple_unlink(dir, dentry);
+               d_delete(dentry);
                dput(dentry);
        }
        inode_unlock(dir);