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From: David Miller <davem@davemloft.net>
To: sudipm.mukherjee@gmail.com
Cc: steve.glendinning@shawell.net, netdev@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usbnet: smsc95xx: dereferencing NULL pointer
Date: Mon, 10 Nov 2014 14:22:23 -0500 (EST)	[thread overview]
Message-ID: <20141110.142223.816257623301941276.davem@davemloft.net> (raw)
In-Reply-To: <1415366560-27614-1-git-send-email-sudipm.mukherjee@gmail.com>

From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Date: Fri,  7 Nov 2014 18:52:40 +0530

> we were dereferencing dev to initialize pdata. but just after that we
> have a BUG_ON(!dev). so we were basically dereferencing the pointer
> first and then tesing it for NULL.
> 
> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>

You didn't even compile test this.

Do not even bother fixing theoretical issues if you're going to be
introducing a _REAL_ serious regression into the code with your "fix":

drivers/net/usb/smsc95xx.c: In function ‘smsc95xx_resume’:
drivers/net/usb/smsc95xx.c:1674:5: warning: ‘pdata’ is used uninitialized in this function [-Wuninitialized]
  u8 suspend_flags = pdata->suspend_flags;
     ^

So, instead of a theoretical issue, we now have a real guaranteed
crash.

You did not compile test this change, and you definitely did not
functionally test this change either.

Please do not do this ever again, thanks.

  reply	other threads:[~2014-11-10 19:22 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-07 13:22 [PATCH] usbnet: smsc95xx: dereferencing NULL pointer Sudip Mukherjee
2014-11-10 19:22 ` David Miller [this message]
2014-11-11  6:30   ` Sudip Mukherjee

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