lkml.org 
[lkml]   [2020]   [May]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.4 067/111] apparmor: fix potential label refcnt leak in aa_change_profile
Date
From: Xiyu Yang <xiyuyang19@fudan.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@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
security/apparmor/domain.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -1334,6 +1334,7 @@ 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;
}
@@ -1352,8 +1353,6 @@ 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 */

\
 
 \ /
  Last update: 2020-05-26 21:09    [W:0.366 / U:0.568 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site