[PATCH] smack: Fix a memory leak in smack_add_opt()

The function is leaking "opts" on the error paths.

Fixes: 90e3b564ab93 ("smack: take the guts of smack_parse_opts_str() into a new helper")
Signed-off-by: Dan Carpenter <redacted>
---
 security/smack/smack_lsm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 2adafc1018d9..4e9cdb942677 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c

@@ -604,13 +604,13 @@ static int smack_add_opt(int token, const char *s, void **mnt_opts)
 {
 	struct smack_mnt_opts *opts = *mnt_opts;
 
+	if (!s)
+		return -ENOMEM;
 	if (!opts) {
 		opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
 		if (!opts)
 			return -ENOMEM;
 	}
-	if (!s)
-		return -ENOMEM;
 
 	switch (token) {
 	case Opt_fsdefault:

@@ -643,6 +643,8 @@ static int smack_add_opt(int token, const char *s, void **mnt_opts)
 	return 0;
 
 out_opt_err:
+	if (opts != *mnt_opts)
+		kfree(opts);
 	pr_warn("Smack: duplicate mount options\n");
 	return -EINVAL;
 }

-- 
2.17.1

On Fri, Dec 21, 2018 at 12:09:58PM +0300, Dan Carpenter wrote:

The function is leaking "opts" on the error paths.

Fixes: 90e3b564ab93 ("smack: take the guts of smack_parse_opts_str() into a new helper")
Signed-off-by: Dan Carpenter <redacted>

D'oh...  Applied, thanks for spotting that braino.

On Fri, Dec 21, 2018 at 04:36:54PM +0000, Al Viro wrote:

On Fri, Dec 21, 2018 at 12:09:58PM +0300, Dan Carpenter wrote:

quoted

The function is leaking "opts" on the error paths.

Fixes: 90e3b564ab93 ("smack: take the guts of smack_parse_opts_str() into a new helper")
Signed-off-by: Dan Carpenter <redacted>

D'oh...  Applied, thanks for spotting that braino.

On the other hand, it's easier to do it this way - the caller will free the damn thing
on error, anyway:

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 11da1e2531c8..cf0c0380e5dd 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c

@@ -608,6 +608,7 @@ static int smack_add_opt(int token, const char *s, void **mnt_opts)
 		opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
 		if (!opts)
 			return -ENOMEM;
+		*mnt_opts = opts;
 	}
 	if (!s)
 		return -ENOMEM;

@@ -639,7 +640,6 @@ static int smack_add_opt(int token, const char *s, void **mnt_opts)
 		opts->fstransmute = s;
 		break;
 	}
-	*mnt_opts = opts;
 	return 0;
 
 out_opt_err:

On 12/21/2018 8:42 AM, Al Viro wrote:

On Fri, Dec 21, 2018 at 04:36:54PM +0000, Al Viro wrote:

quoted

On Fri, Dec 21, 2018 at 12:09:58PM +0300, Dan Carpenter wrote:

quoted

The function is leaking "opts" on the error paths.

Fixes: 90e3b564ab93 ("smack: take the guts of smack_parse_opts_str() into a new helper")
Signed-off-by: Dan Carpenter <redacted>

D'oh...  Applied, thanks for spotting that braino.

On the other hand, it's easier to do it this way - the caller will free the damn thing
on error, anyway:

What tree/branch is the happening in?