[PATCH 5.4 095/320] selinux: fix potential memleak in selinux_add_opt()

Greg Kroah-Hartman
2022-01-24T19:32:34Z

From: Bernard Zhao <bernard@vivo.com>

[ Upstream commit 2e08df3c7c4e4e74e3dd5104c100f0bf6288aaa8 ]

This patch try to fix potential memleak in error branch.

Fixes: ba6418623385 ("selinux: new helper - selinux_add_opt()")
Signed-off-by: Bernard Zhao <bernard@vivo.com>
[PM: tweak the subject line, add Fixes tag]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
security/selinux/hooks.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 91f2ba0b225b7..56418cf72069d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -995,18 +995,22 @@ out:
static int selinux_add_opt(int token, const char *s, void **mnt_opts)
{
struct selinux_mnt_opts *opts = *mnt_opts;
+ bool is_alloc_opts = false;

if (token == Opt_seclabel) /* eaten and completely ignored */
return 0;

+ if (!s)
+ return -ENOMEM;
+
if (!opts) {
opts = kzalloc(sizeof(struct selinux_mnt_opts), GFP_KERNEL);
if (!opts)
return -ENOMEM;
*mnt_opts = opts;
+ is_alloc_opts = true;
}
- if (!s)
- return -ENOMEM;
+
switch (token) {
case Opt_context:
if (opts->context || opts->defcontext)
@@ -1031,6 +1035,10 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts)
}
return 0;
Einval:
+ if (is_alloc_opts) {
+ kfree(opts);
+ *mnt_opts = NULL;
+ }
pr_warn(SEL_MOUNT_FAIL_MSG);
return -EINVAL;
}
--
2.34.1