[PATCH 3/4] net: wirelesse: wcn36xx: pull allocation outside of critical section

Eugene Krasnikov k.eugene.e at gmail.com
Tue Feb 11 14:37:37 EST 2014


From: Michal Nazarewicz <mina86 at mina86.com>

Commit [3469adb3: fix potential NULL pointer dereference] introduced
a check of msg_ind allocation, but omitted allocation of msg_ind->msg.
Moreover, it introduced two if statements, which looked a bit clunky.

This commit moves allocation code outside of the critical section so
there's no need to dance around mutex_unlock, and adds the missing
allocation check.

Signed-off-by: Michal Nazarewicz <mina86 at mina86.com>
Signed-off-by: John W. Linville <linville at tuxdriver.com>
---
 smd.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/smd.c b/smd.c
index e78667f..0feb4fc 100644
--- a/smd.c
+++ b/smd.c
@@ -2067,22 +2067,28 @@ static void wcn36xx_smd_rsp_process(struct wcn36xx *wcn, void *buf, size_t len)
 	case WCN36XX_HAL_OTA_TX_COMPL_IND:
 	case WCN36XX_HAL_MISSED_BEACON_IND:
 	case WCN36XX_HAL_DELETE_STA_CONTEXT_IND:
-		mutex_lock(&wcn->hal_ind_mutex);
 		msg_ind = kmalloc(sizeof(*msg_ind), GFP_KERNEL);
-		if (msg_ind) {
-			msg_ind->msg_len = len;
-			msg_ind->msg = kmalloc(len, GFP_KERNEL);
-			memcpy(msg_ind->msg, buf, len);
-			list_add_tail(&msg_ind->list, &wcn->hal_ind_queue);
-			queue_work(wcn->hal_ind_wq, &wcn->hal_ind_work);
-			wcn36xx_dbg(WCN36XX_DBG_HAL, "indication arrived\n");
+		if (!msg_ind)
+			goto nomem;
+		msg_ind->msg_len = len;
+		msg_ind->msg = kmalloc(len, GFP_KERNEL);
+		if (!msg_ind->msg) {
+			kfree(msg_ind);
+nomem:
+			/*
+			 * FIXME: Do something smarter then just
+			 * printing an error.
+			 */
+			wcn36xx_err("Run out of memory while handling SMD_EVENT (%d)\n",
+				    msg_header->msg_type);
+			break;
 		}
+		memcpy(msg_ind->msg, buf, len);
+		mutex_lock(&wcn->hal_ind_mutex);
+		list_add_tail(&msg_ind->list, &wcn->hal_ind_queue);
+		queue_work(wcn->hal_ind_wq, &wcn->hal_ind_work);
 		mutex_unlock(&wcn->hal_ind_mutex);
-		if (msg_ind)
-			break;
-		/* FIXME: Do something smarter then just printing an error. */
-		wcn36xx_err("Run out of memory while handling SMD_EVENT (%d)\n",
-			    msg_header->msg_type);
+		wcn36xx_dbg(WCN36XX_DBG_HAL, "indication arrived\n");
 		break;
 	default:
 		wcn36xx_err("SMD_EVENT (%d) not supported\n",
-- 
1.8.3.2




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