Re: [PATCH] Fix problem with size of allocation in libsas

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Mon, 2007-11-12 at 00:24 +0100, Jesper Juhl wrote:
> From: Jesper Juhl <jesper.juhl@gmail.com>
> 
> in sas_get_phy_change_count(), the line
> 	disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
> will allocate 56 bytes due to this define:
> 	#define DISCOVER_RESP_SIZE 56
> But, the struct is actually 60 bytes in size.
> 
> So change the define to be 
> 	#define DISCOVER_RESP_SIZE sizeof(struct smp_resp)
> so we always get the correct size even when people 
> fiddle with the structure.
> 
> This change also fixes the same problem in 
> sas_get_phy_attached_sas_addr()
> 
> (Found by the Coverity checker. Compile tested only)

Well, your fix is definitely wrong.

Could you explain the problem a little more?  The discover response SMP
frame is 56 bytes as mandated by the standard.  I don't see anywhere in
the code where we're actually using a value beyond the 56th byte ...
where is the problem use?

James