Re: [PATCH][wireless-next] qtnfmac: check band before allocating cmd_skb to avoid resource leak

[Igor Mitsyanko]

On 06/02/2017 08:40 AM, Colin King wrote:

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From: Colin Ian King <colin.k...@canonical.com>

The current code allocates cmd_skb and then will leak this if band->band
is an illegal value. It is simpler to sanity check the band first before
allocating cmd_skb so that we don't have to free cmd_skb if an invalid
band occurs.

Detected by CoverityScan, CID#1437561 ("Resource Leak")

Signed-off-by: Colin Ian King <colin.k...@canonical.com>
---
  drivers/net/wireless/quantenna/qtnfmac/commands.c | 12 ++++++------
  1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/quantenna/qtnfmac/commands.c 
b/drivers/net/wireless/quantenna/qtnfmac/commands.c
index f0a0cfa7d8a1..cce62f39edaf 100644
--- a/drivers/net/wireless/quantenna/qtnfmac/commands.c
+++ b/drivers/net/wireless/quantenna/qtnfmac/commands.c
@@ -1300,12 +1300,6 @@ int qtnf_cmd_get_mac_chan_info(struct qtnf_wmac *mac,
         int ret = 0;
         u8 qband;

-       cmd_skb = qtnf_cmd_alloc_new_cmdskb(mac->macid, 0,
-                                           QLINK_CMD_CHANS_INFO_GET,
-                                           sizeof(*cmd));
-       if (!cmd_skb)
-               return -ENOMEM;
-
         switch (band->band) {
         case NL80211_BAND_2GHZ:
                 qband = QLINK_BAND_2GHZ;
@@ -1320,6 +1314,12 @@ int qtnf_cmd_get_mac_chan_info(struct qtnf_wmac *mac,
                 return -EINVAL;
         }

+       cmd_skb = qtnf_cmd_alloc_new_cmdskb(mac->macid, 0,
+                                           QLINK_CMD_CHANS_INFO_GET,
+                                           sizeof(*cmd));
+       if (!cmd_skb)
+               return -ENOMEM;
+
         cmd = (struct qlink_cmd_chans_info_get *)cmd_skb->data;
         cmd->band = qband;
         ret = qtnf_cmd_send_with_reply(mac->bus, cmd_skb, &resp_skb, &res_code,
--
2.11.0

Reviewed-by: Igor Mitsyanko <igor.mitsyanko...@quantenna.com>