[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20200526183944.505936788@linuxfoundation.org>
Date: Tue, 26 May 2020 20:53:32 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Xiyu Yang <xiyuyang19@...an.edu.cn>,
Xin Tan <tanxin.ctf@...il.com>,
John Johansen <john.johansen@...onical.com>
Subject: [PATCH 5.6 075/126] apparmor: fix potential label refcnt leak in aa_change_profile
From: Xiyu Yang <xiyuyang19@...an.edu.cn>
commit a0b845ffa0d91855532b50fc040aeb2d8338dca4 upstream.
aa_change_profile() invokes aa_get_current_label(), which returns
a reference of the current task's label.
According to the comment of aa_get_current_label(), the returned
reference must be put with aa_put_label().
However, when the original object pointed by "label" becomes
unreachable because aa_change_profile() returns or a new object
is assigned to "label", reference count increased by
aa_get_current_label() is not decreased, causing a refcnt leak.
Fix this by calling aa_put_label() before aa_change_profile() return
and dropping unnecessary aa_get_current_label().
Fixes: 9fcf78cca198 ("apparmor: update domain transitions that are subsets of confinement at nnp")
Signed-off-by: Xiyu Yang <xiyuyang19@...an.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@...il.com>
Signed-off-by: John Johansen <john.johansen@...onical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
security/apparmor/domain.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -1328,6 +1328,7 @@ int aa_change_profile(const char *fqname
ctx->nnp = aa_get_label(label);
if (!fqname || !*fqname) {
+ aa_put_label(label);
AA_DEBUG("no profile name");
return -EINVAL;
}
@@ -1346,8 +1347,6 @@ int aa_change_profile(const char *fqname
op = OP_CHANGE_PROFILE;
}
- label = aa_get_current_label();
-
if (*fqname == '&') {
stack = true;
/* don't have label_parse() do stacking */
Powered by blists - more mailing lists