From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ralf Baechle Subject: Re: [PATCH] ax25: Fix use of copy_from_sockptr() in ax25_setsockopt() Date: Tue, 12 Oct 2021 19:10:23 +0200 Message-ID: References: <20211012062309.GD17407@lst.de> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20211012062309.GD17407@lst.de> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Hellwig Cc: netdev@vger.kernel.org, "David S. Miller" , Jakub Kicinski , Thomas Osterried , linux-hams@vger.kernel.org On Tue, Oct 12, 2021 at 08:23:09AM +0200, Christoph Hellwig wrote: > On Thu, Sep 30, 2021 at 06:24:35PM +0200, Ralf Baechle wrote: > > The destination pointer passed to copy_from_sockptr() is an unsigned long * > > but the source in userspace is an unsigned int * resulting in an integer > > of the wrong size being copied from userspace. > > > > This happens to work on 32 bit but breaks 64-bit where bytes 4..7 will not > > be initialized. By luck it may work on little endian but on big endian > > where the userspace data is copied to the upper 32 bit of the destination > > it's most likely going to break. > > > > A simple test case to demonstrate this setsockopt() issue is: > > Looks good, > > Reviewed-by: Christoph Hellwig Sadly the kernel test robot has raised a bunch of warnings in this patch. To fix those I'll pull a few fixes from another patch I was planning to send later and merge them into this patch and post the resulting patch as v2. Thanks for the review, Ralf