tree 5c8de2d138cd172138ab19c204884366960a6f55
parent a0b845ffa0d91855532b50fc040aeb2d8338dca4
author Xiyu Yang <xiyuyang19@fudan.edu.cn> 1587360928 +0800
committer John Johansen <john.johansen@canonical.com> 1590099951 -0700

apparmor: Fix aa_label refcnt leak in policy_update

policy_update() invokes begin_current_label_crit_section(), which
returns a reference of the updated aa_label object to "label" with
increased refcount.

When policy_update() returns, "label" becomes invalid, so the refcount
should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
policy_update(). When aa_may_manage_policy() returns not NULL, the
refcnt increased by begin_current_label_crit_section() is not decreased,
causing a refcnt leak.

Fix this issue by jumping to "end_section" label when
aa_may_manage_policy() returns not NULL.

Fixes: 5ac8c355ae00 ("apparmor: allow introspecting the loaded policy pre internal transform")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>