From: Xin Xiong <xiongx18@fudan.edu.cn> Date: Thu, 28 Apr 2022 03:39:08 +0000 (+0800) Subject: apparmor: fix reference count leak in aa_pivotroot() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=64103ea357734b82384c925cba4758fdb909be0c;p=linux.git 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: 2ea3ffb7782a ("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> --- diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c index 23aafe68d49a9..f7bb47daf2ad6 100644 --- a/security/apparmor/mount.c +++ b/security/apparmor/mount.c @@ -719,6 +719,7 @@ 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);