apparmor: fix reference count leak in aa_pivotroot()

commit 11c3627ec6b56c1525013f336f41b79a983b4d46 upstream.

The aa_pivotroot() function has a reference counting bug in a specific
path. When aa_replace_current_label() returns on success, the function
forgets to decrement the reference count of “target”, which is
increased earlier by build_pivotroot(), causing a reference leak.

Fix it by decreasing the refcount of “target” in that path.

Fixes: 2ea3ffb778 ("apparmor: add mount mediation")
Co-developed-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Co-developed-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Xin Xiong 2022-04-28 11:39:08 +08:00 committed by Greg Kroah-Hartman
parent 7f6092dc8f
commit ef6fb6f0d0

View File

@ -683,6 +683,7 @@ int aa_pivotroot(struct aa_label *label, const struct path *old_path,
aa_put_label(target); aa_put_label(target);
goto out; goto out;
} }
aa_put_label(target);
} else } else
/* already audited error */ /* already audited error */
error = PTR_ERR(target); error = PTR_ERR(target);