[apparmor] [PATCH] apparmor: aa_getprocattr free procattr leak on format failure

[Zygmunt Krynicki]

aa_getprocattr() allocates the output string before rendering the label
into it. If the second aa_label_snxprint() call fails, the function
returned without freeing that allocation.

Free and clear the output pointer on the uncommon formatting failure path
before dropping the namespace reference.

Signed-off-by: Zygmunt Krynicki <me at zygoon.pl>
---
 security/apparmor/procattr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/security/apparmor/procattr.c b/security/apparmor/procattr.c
index ce40f15d4952d..c07b6e8fd9c93 100644
--- a/security/apparmor/procattr.c
+++ b/security/apparmor/procattr.c
@@ -54,6 +54,8 @@ int aa_getprocattr(struct aa_label *label, char **string, bool newline)
 				FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
 				FLAG_HIDDEN_UNCONFINED);
 	if (len < 0) {
+		kfree(*string);
+		*string = NULL;
 		aa_put_ns(current_ns);
 		return len;
 	}
-- 
2.53.0