This seems to have fallen off the radar.  I've pulled it into my tree, so it'll 
eventually be pulled into master.

--Jeremy

On Oct 4, 2011, at 2:25 AM, Rami Ylimäki wrote:

> Any pad bytes in replies are written to the client from a zeroed
> array. However, record extension tries to incorrectly access the pad
> bytes from the end of reply data.
> 
> Signed-off-by: Rami Ylimäki <[email protected]>
> Reviewed-by: Erkki Seppälä <[email protected]>
> ---
> v1: Fixed the issue when a reply was cached into a recording context buffer.
> v2: Fixes the issue also for large replies that don't fit into the cache.
> 
> include/os.h    |    3 ++-
> os/io.c         |    1 +
> record/record.c |   53 ++++++++++++++++++++++++++++++-----------------------
> 3 files changed, 33 insertions(+), 24 deletions(-)
> 
> diff --git a/include/os.h b/include/os.h
> index 5401ea4..fda0181 100644
> --- a/include/os.h
> +++ b/include/os.h
> @@ -451,9 +451,10 @@ extern _X_EXPORT CallbackListPtr ReplyCallback;
> typedef struct {
>     ClientPtr client;
>     const void *replyData;
> -    unsigned long dataLenBytes;
> +    unsigned long dataLenBytes; /* actual bytes from replyData + pad bytes */
>     unsigned long bytesRemaining;
>     Bool startOfReply;
> +    unsigned long padBytes;     /* pad bytes from zeroed array */
> } ReplyInfoRec;
> 
> /* stuff for FlushCallback */
> diff --git a/os/io.c b/os/io.c
> index 068f5f0..955bf8b 100644
> --- a/os/io.c
> +++ b/os/io.c
> @@ -809,6 +809,7 @@ WriteToClient (ClientPtr who, int count, const void 
> *__buf)
>       replyinfo.client = who;
>       replyinfo.replyData = buf;
>       replyinfo.dataLenBytes = count + padBytes;
> +     replyinfo.padBytes = padBytes;
>       if (who->replyBytesRemaining)
>       { /* still sending data of an earlier reply */
>           who->replyBytesRemaining -= count + padBytes;
> diff --git a/record/record.c b/record/record.c
> index 68311ac..db77b64 100644
> --- a/record/record.c
> +++ b/record/record.c
> @@ -269,8 +269,9 @@ RecordFlushReplyBuffer(
>  *      device events and EndOfData, pClient is NULL.
>  *    category is the category of the protocol element, as defined
>  *      by the RECORD spec.
> - *   data is a pointer to the protocol data, and datalen is its length
> - *     in bytes.
> + *   data is a pointer to the protocol data, and datalen - padlen
> + *     is its length in bytes.
> + *   padlen is the number of pad bytes from a zeroed array.
>  *    futurelen is the number of bytes that will be sent in subsequent
>  *      calls to this function to complete this protocol element.  
>  *      In those subsequent calls, futurelen will be -1 to indicate
> @@ -290,7 +291,7 @@ RecordFlushReplyBuffer(
>  */
> static void
> RecordAProtocolElement(RecordContextPtr pContext, ClientPtr pClient,
> -                    int category, pointer data, int datalen, int futurelen)
> +                    int category, pointer data, int datalen, int padlen, int 
> futurelen)
> {
>     CARD32 elemHeaderData[2];
>     int numElemHeaders = 0;
> @@ -398,15 +399,20 @@ RecordAProtocolElement(RecordContextPtr pContext, 
> ClientPtr pClient,
>       }
>       if (datalen)
>       {
> +         static char padBuffer[3]; /* as in FlushClient */
>           memcpy(pContext->replyBuffer + pContext->numBufBytes,
> -                data, datalen);
> -         pContext->numBufBytes += datalen;
> +                data, datalen - padlen);
> +         pContext->numBufBytes += datalen - padlen;
> +         memcpy(pContext->replyBuffer + pContext->numBufBytes,
> +                padBuffer, padlen);
> +         pContext->numBufBytes += padlen;
>       }
>     }
>     else
> +    {
>       RecordFlushReplyBuffer(pContext, (pointer)elemHeaderData,
> -                            numElemHeaders, (pointer)data, datalen);
> -
> +                            numElemHeaders, (pointer)data, datalen - padlen);
> +    }
> } /* RecordAProtocolElement */
> 
> 
> @@ -483,19 +489,19 @@ RecordABigRequest(RecordContextPtr pContext, ClientPtr 
> client, xReq *stuff)
>     /* record the request header */
>     bytesLeft = client->req_len << 2;
>     RecordAProtocolElement(pContext, client, XRecordFromClient,
> -                        (pointer)stuff, SIZEOF(xReq), bytesLeft);
> +                        (pointer)stuff, SIZEOF(xReq), 0, bytesLeft);
> 
>     /* reinsert the extended length field that was squished out */
>     bigLength = client->req_len + bytes_to_int32(sizeof(bigLength));
>     if (client->swapped)
>       swapl(&bigLength);
>     RecordAProtocolElement(pContext, client, XRecordFromClient,
> -             (pointer)&bigLength, sizeof(bigLength), /* continuation */ -1);
> +               (pointer)&bigLength, sizeof(bigLength), 0, /* continuation */ 
> -1);
>     bytesLeft -= sizeof(bigLength);
> 
>     /* record the rest of the request after the length */
>     RecordAProtocolElement(pContext, client, XRecordFromClient,
> -             (pointer)(stuff + 1), bytesLeft, /* continuation */ -1);
> +               (pointer)(stuff + 1), bytesLeft, 0, /* continuation */ -1);
> } /* RecordABigRequest */
> 
> 
> @@ -542,7 +548,7 @@ RecordARequest(ClientPtr client)
>                   RecordABigRequest(pContext, client, stuff);
>               else
>                   RecordAProtocolElement(pContext, client, XRecordFromClient,
> -                             (pointer)stuff, client->req_len << 2, 0);
> +                             (pointer)stuff, client->req_len << 2, 0, 0);
>           }
>           else /* extension, check minor opcode */
>           {
> @@ -566,7 +572,7 @@ RecordARequest(ClientPtr client)
>                       else
>                           RecordAProtocolElement(pContext, client, 
>                                       XRecordFromClient, (pointer)stuff,
> -                                     client->req_len << 2, 0);
> +                                     client->req_len << 2, 0, 0);
>                       break;
>                   }                       
>               } /* end for each minor op info */
> @@ -619,7 +625,8 @@ RecordAReply(CallbackListPtr *pcbl, pointer nulldata, 
> pointer calldata)
>           if (pContext->continuedReply)
>           {
>               RecordAProtocolElement(pContext, client, XRecordFromServer,
> -                (pointer)pri->replyData, pri->dataLenBytes, /* continuation 
> */ -1);
> +                (pointer)pri->replyData, pri->dataLenBytes,
> +                         pri->padBytes, /* continuation */ -1);
>               if (!pri->bytesRemaining)
>                   pContext->continuedReply = 0;
>           }
> @@ -629,7 +636,7 @@ RecordAReply(CallbackListPtr *pcbl, pointer nulldata, 
> pointer calldata)
>               if (majorop <= 127)
>               { /* core reply */
>                   RecordAProtocolElement(pContext, client, XRecordFromServer,
> -                    (pointer)pri->replyData, pri->dataLenBytes, 
> pri->bytesRemaining);
> +                    (pointer)pri->replyData, pri->dataLenBytes, 0, 
> pri->bytesRemaining);
>                   if (pri->bytesRemaining)
>                       pContext->continuedReply = 1;
>               }
> @@ -651,7 +658,7 @@ RecordAReply(CallbackListPtr *pcbl, pointer nulldata, 
> pointer calldata)
>                       {
>                           RecordAProtocolElement(pContext, client, 
>                               XRecordFromServer, (pointer)pri->replyData,
> -                             pri->dataLenBytes, pri->bytesRemaining);
> +                             pri->dataLenBytes, 0, pri->bytesRemaining);
>                           if (pri->bytesRemaining)
>                               pContext->continuedReply = 1;
>                           break;
> @@ -723,7 +730,7 @@ RecordADeliveredEventOrError(CallbackListPtr *pcbl, 
> pointer nulldata, pointer ca
>                       
>                   }
>                   RecordAProtocolElement(pContext, pClient,
> -                     XRecordFromServer, pEvToRecord, SIZEOF(xEvent), 0);
> +                     XRecordFromServer, pEvToRecord, SIZEOF(xEvent), 0, 0);
>               }
>           } /* end for each event */
>       } /* end this client is on this context */
> @@ -774,7 +781,7 @@ RecordSendProtocolEvents(RecordClientsAndProtocolPtr 
> pRCAP,
>           }
> 
>           RecordAProtocolElement(pContext, NULL,
> -                 XRecordFromServer,  pEvToRecord, SIZEOF(xEvent), 0);
> +                 XRecordFromServer,  pEvToRecord, SIZEOF(xEvent), 0, 0);
>           /* make sure device events get flushed in the absence
>            * of other client activity
>            */
> @@ -2415,7 +2422,7 @@ ProcRecordEnableContext(ClientPtr client)
>     assert(numEnabledContexts > 0);
> 
>     /* send StartOfData */
> -    RecordAProtocolElement(pContext, NULL, XRecordStartOfData, NULL, 0, 0);
> +    RecordAProtocolElement(pContext, NULL, XRecordStartOfData, NULL, 0, 0, 
> 0);
>     RecordFlushReplyBuffer(pContext, NULL, 0, NULL, 0);
>     return Success;
> } /* ProcRecordEnableContext */
> @@ -2446,7 +2453,7 @@ RecordDisableContext(RecordContextPtr pContext)
>     if (!pContext->pRecordingClient) return;
>     if (!pContext->pRecordingClient->clientGone)
>     {
> -     RecordAProtocolElement(pContext, NULL, XRecordEndOfData, NULL, 0, 0);
> +     RecordAProtocolElement(pContext, NULL, XRecordEndOfData, NULL, 0, 0, 0);
>       RecordFlushReplyBuffer(pContext, NULL, 0, NULL, 0);
>       /* Re-enable request processing on this connection. */
>       AttendClient(pContext->pRecordingClient);
> @@ -2761,7 +2768,7 @@ RecordConnectionSetupInfo(RecordContextPtr pContext, 
> NewClientInfoRec *pci)
>       SwapConnSetupPrefix(pci->prefix, (xConnSetupPrefix*)pConnSetup);
>       SwapConnSetupInfo((char*)pci->setup, (char*)(pConnSetup + prefixsize));
>       RecordAProtocolElement(pContext, pci->client, XRecordClientStarted,
> -                            (pointer)pConnSetup, prefixsize + restsize, 0);
> +                            (pointer)pConnSetup, prefixsize + restsize, 0, 
> 0);
>       free(pConnSetup);
>     }
>     else
> @@ -2770,9 +2777,9 @@ RecordConnectionSetupInfo(RecordContextPtr pContext, 
> NewClientInfoRec *pci)
>        * data in two pieces
>        */
>       RecordAProtocolElement(pContext, pci->client, XRecordClientStarted,
> -                     (pointer)pci->prefix, prefixsize, restsize);
> +                     (pointer)pci->prefix, prefixsize, 0, restsize);
>       RecordAProtocolElement(pContext, pci->client, XRecordClientStarted,
> -                     (pointer)pci->setup, restsize, /* continuation */ -1);
> +                     (pointer)pci->setup, restsize, 0, /* continuation */ 
> -1);
>     }
> } /* RecordConnectionSetupInfo */
> 
> @@ -2849,7 +2856,7 @@ RecordAClientStateChange(CallbackListPtr *pcbl, pointer 
> nulldata, pointer callda
>           {
>               if (pContext->pRecordingClient && pRCAP->clientDied)
>                   RecordAProtocolElement(pContext, pClient,
> -                                        XRecordClientDied, NULL, 0, 0);
> +                                        XRecordClientDied, NULL, 0, 0, 0);
>               RecordDeleteClientFromRCAP(pRCAP, pos);
>           }
>       }
> -- 
> 1.7.1
> 
> _______________________________________________
> [email protected]: X.Org development
> Archives: http://lists.x.org/archives/xorg-devel
> Info: http://lists.x.org/mailman/listinfo/xorg-devel



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