NFC: Fix possible LLCP memory leak

nfc_llcp_build_tlv() malloced the memory and should be free in
nfc_llcp_build_gb() after used, and the same in the error handling
case, otherwise it will cause memory leak.

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/net/nfc/llcp/llcp.c b/net/nfc/llcp/llcp.c
index 6f368412ffd2..90ef4a176819 100644
--- a/net/nfc/llcp/llcp.c
+++ b/net/nfc/llcp/llcp.c
@@ -426,6 +426,7 @@ static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
         u8 *miux_tlv, miux_length;
         __be16 miux;
         u8 gb_len = 0;
+        int ret = 0;
 
         version = LLCP_VERSION_11;
         version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
@@ -450,8 +451,8 @@ static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
         gb_len += ARRAY_SIZE(llcp_magic);
 
         if (gb_len > NFC_MAX_GT_LEN) {
-                kfree(version_tlv);
-                return -EINVAL;
+                ret = -EINVAL;
+                goto out;
         }
 
         gb_cur = local->gb;
@@ -471,12 +472,15 @@ static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
         memcpy(gb_cur, miux_tlv, miux_length);
         gb_cur += miux_length;
 
+        local->gb_len = gb_len;
+
+out:
         kfree(version_tlv);
         kfree(lto_tlv);
+        kfree(wks_tlv);
+        kfree(miux_tlv);
 
-        local->gb_len = gb_len;
-
-        return 0;
+        return ret;
 }
 
 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)