Re: xprtrdma: Prevent inline overflow

[Colin Ian King <colin.king@canonical.com>]

On 15/07/2020 17:05, Chuck Lever wrote:
> 
> 
>> On Jul 15, 2020, at 11:56 AM, Colin Ian King <colin.king@canonical.com> wrote:
>>
>> Hi,
>>
>> Static analysis with Coverity has found a potential issue with the
>> header size calculations in source net/sunrpc/xprtrdma/rpc_rdma.c in
>> functions rpcrdma_max_call_header_size and rpcrdma_max_reply_header_size.
>>
>> The commit in question is relatively old:
>>
>> commit 302d3deb20682a076e1ab551821cacfdc81c5e4f
>> Author: Chuck Lever <chuck.lever@oracle.com>
>> Date:   Mon May 2 14:41:05 2016 -0400
>>
>>    xprtrdma: Prevent inline overflow
>>
>> The two issues are as follows:
>>
>> Issue #1:
>>
>> 66 static unsigned int rpcrdma_max_call_header_size(unsigned int maxsegs)
>> 67 {
>> 68        unsigned int size;
>> 69
>> 70        /* Fixed header fields and list discriminators */
>>
>> Unused value (UNUSED_VALUE)
>>
>> 71        size = RPCRDMA_HDRLEN_MIN;
>> 72
>> 73        /* Maximum Read list size */
>> 74        size = maxsegs * rpcrdma_readchunk_maxsz * sizeof(__be32);
>> 75
>>
>> should the size assignment on line 74 be instead:
>>
>> 	size += maxsegs * rpcrdma_readchunk_maxsz * sizeof(__be32);
>>
>>
>> Issue #2:
>>
>> 89 static unsigned int rpcrdma_max_reply_header_size(unsigned int maxsegs)
>> 90 {
>> 91        unsigned int size;
>> 92
>> 93        /* Fixed header fields and list discriminators */
>>
>> Unused value (UNUSED_VALUE)
>>
>> 94        size = RPCRDMA_HDRLEN_MIN;
>> 95
>> 96        /* Maximum Write list size */
>> 97        size = sizeof(__be32);          /* segment count */
>>
>> should the size assignment in line 97 be instead:
>>
>> 	size += sizeof(__be32)?
> 
> Colin, Yes to both questions. Can you send a fix to Anna?

OK, thanks for confirming. Will send a fix in the next hour or so.

Colin
> 
> --
> Chuck Lever
> 
> 
>