Re: [2.6 patch] drivers/net/wireless/libertas/fw.c: fix use-before-check

[Eugene Teo <eteo@redhat.com>]

Hi John,

John W. Linville wrote:
> On Sat, May 19, 2007 at 01:06:49AM +0800, Eugene Teo wrote:
>> NULL checks should be performed before the dereference.
>>
>> Spotted by the Coverity checker.
>>
>> Signed-off-by: Eugene Teo <eteo@redhat.com>
> 
> This does not apply against 2.6.22-rc1.  Please rediff and repost.

Ok. Here's a rediff against 2.6.22-rc1. Thanks.
--

NULL checks should be performed before the dereference.

Spotted by the Coverity checker.

Signed-off-by: Eugene Teo <eteo@redhat.com>

diff -uprN -X 2.6.22-rc1/Documentation/dontdiff
2.6.22-rc1.orig/drivers/net/wireless/libertas/fw.c 2.6.22-rc1/drivers/net/wireless/libertas/fw.c
--- 2.6.22-rc1.orig/drivers/net/wireless/libertas/fw.c  2007-05-19 10:48:02.000000000 +0800
+++ 2.6.22-rc1/drivers/net/wireless/libertas/fw.c       2007-05-19 11:01:26.000000000 +0800
@@ -333,18 +333,22 @@ static void command_timer_fn(unsigned lo
        unsigned long flags;

        ptempnode = adapter->cur_cmd;
+       if (ptempnode == NULL) {
+               lbs_pr_debug(1, "PTempnode Empty\n");
+               return;
+       }
+
        cmd = (struct cmd_ds_command *)ptempnode->bufvirtualaddr;
+       if (!cmd) {
+               lbs_pr_debug(1, "cmd is NULL\n");
+               return;
+       }

        lbs_pr_info("command_timer_fn fired (%x)\n", cmd->command);

        if (!adapter->fw_ready)
                return;

-       if (ptempnode == NULL) {
-               lbs_pr_debug(1, "PTempnode Empty\n");
-               return;
-       }
-
        spin_lock_irqsave(&adapter->driver_lock, flags);
        adapter->cur_cmd = NULL;
        spin_unlock_irqrestore(&adapter->driver_lock, flags);