iwlwifi: fix freeing uninitialized pointer
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
Cc: stable@vger.kernel.org
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>
diff --git a/drivers/net/wireless/iwlwifi/dvm/debugfs.c b/drivers/net/wireless/iwlwifi/dvm/debugfs.c
index 7b8178b..cb6dd58 100644
--- a/drivers/net/wireless/iwlwifi/dvm/debugfs.c
+++ b/drivers/net/wireless/iwlwifi/dvm/debugfs.c
@@ -2237,15 +2237,15 @@
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;
}