Commit ef6fb6f0 authored Apr 28, 2022 by Xin Xiong Committed by Greg Kroah-Hartman Aug 25, 2022

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: 2ea3ffb7 ("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>

parent 7f6092dc

security/apparmor/mount.c

+1 −0

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