[PATCH v5] cifs: Allocate validate negotiation request through kmalloc

[Tom Talpey]

> -----Original Message-----
> From: linux-cifs-owner at vger.kernel.org <linux-cifs-owner at vger.kernel.org> On
> Behalf Of Long Li
> Sent: Wednesday, April 25, 2018 2:30 PM
> To: Steve French <sfrench at samba.org>; linux-cifs at vger.kernel.org; samba-
> technical at lists.samba.org; linux-kernel at vger.kernel.org; linux-
> rdma at vger.kernel.org
> Cc: Long Li <longli at microsoft.com>
> Subject: [PATCH v5] cifs: Allocate validate negotiation request through kmalloc
> 
> From: Long Li <longli at microsoft.com>
> 
> The data buffer allocated on the stack can't be DMA'ed, ib_dma_map_page will
> return an invalid DMA address for a buffer on stack. Even worse, this
> incorrect address can't be detected by ib_dma_mapping_error. Sending data
> from this address to hardware will not fail, but the remote peer will get
> junk data.
> 
> Fix this by allocating the request on the heap in smb3_validate_negotiate.
> 

Looks good.

Reviewed-By: Tom Talpey <ttalpey at microsoft.com>