From: Stanislaw Gruszka <sgruszka@redhat.com>
Date: Tue, 16 Apr 2013 13:38:29 +0000 (+0200)
Subject: iwlwifi: fix freeing uninitialized pointer
X-Git-Tag: v3.9.1~100
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=34e3e78befc3c6f65f3e7ce70f0367745cd550b0;p=karo-tx-linux.git

iwlwifi: fix freeing uninitialized pointer

commit 3309ccf7fcebceef540ebe90c65d2f94d745a45b upstream.

If on iwl_dump_nic_event_log() error occurs before that function
initialize buf, we process uninitiated pointer in
iwl_dbgfs_log_event_read() and can hit "BUG at mm/slub.c:3409"

Resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=951241

Reported-by: ian.odette@eprize.com
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/wireless/iwlwifi/dvm/debugfs.c b/drivers/net/wireless/iwlwifi/dvm/debugfs.c
index 20806cae11b7..81d4071130c1 100644
--- a/drivers/net/wireless/iwlwifi/dvm/debugfs.c
+++ b/drivers/net/wireless/iwlwifi/dvm/debugfs.c
@@ -2237,15 +2237,15 @@ static ssize_t iwl_dbgfs_log_event_read(struct file *file,
 					 size_t count, loff_t *ppos)
 {
 	struct iwl_priv *priv = file->private_data;
-	char *buf;
-	int pos = 0;
-	ssize_t ret = -ENOMEM;
+	char *buf = NULL;
+	ssize_t ret;
 
-	ret = pos = iwl_dump_nic_event_log(priv, true, &buf, true);
-	if (buf) {
-		ret = simple_read_from_buffer(user_buf, count, ppos, buf, pos);
-		kfree(buf);
-	}
+	ret = iwl_dump_nic_event_log(priv, true, &buf, true);
+	if (ret < 0)
+		goto err;
+	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+err:
+	kfree(buf);
 	return ret;
 }