apparmor: fix potential label refcnt leak in aa_change_profile
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>
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 6ceb74e..a84ef03 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -1328,6 +1328,7 @@
ctx->nnp = aa_get_label(label);
if (!fqname || !*fqname) {
+ aa_put_label(label);
AA_DEBUG("no profile name");
return -EINVAL;
}
@@ -1346,8 +1347,6 @@
op = OP_CHANGE_PROFILE;
}
- label = aa_get_current_label();
-
if (*fqname == '&') {
stack = true;
/* don't have label_parse() do stacking */
