From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:60589) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RqSIJ-0000ln-7S for qemu-devel@nongnu.org; Thu, 26 Jan 2012 11:35:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RqSIC-0003V0-I6 for qemu-devel@nongnu.org; Thu, 26 Jan 2012 11:35:26 -0500 Received: from mx1.redhat.com ([209.132.183.28]:15104) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RqSIC-0003Um-BV for qemu-devel@nongnu.org; Thu, 26 Jan 2012 11:35:20 -0500 From: Kevin Wolf Date: Thu, 26 Jan 2012 17:38:16 +0100 Message-Id: <1327595896-19623-23-git-send-email-kwolf@redhat.com> In-Reply-To: <1327595896-19623-1-git-send-email-kwolf@redhat.com> References: <1327595896-19623-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH 22/22] scsi: Guard against buflen exceeding req->cmd.xfer in scsi_disk_emulate_command List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: anthony@codemonkey.ws Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Thomas Higdon Limit the return value (corresponding to the length of the buffer to be DMAed back to the intiator) to the value in req->cmd.xfer, which is the amount of data that the initiator expects. Eliminate now-duplicate code that does this guarding in the functions for individual commands. Without this, the SCRIPTS code in the emulated LSI device eventually raises a DMA interrupt for a data overrun when an INQUIRY command whose buflen exceeds req->cmd.xfer is processed. It's the responsibility of the client to provide a request buffer and allocation length that are large enough for the result of the command. Signed-off-by: Thomas Higdon Reviewed-by: Paolo Bonzini Signed-off-by: Kevin Wolf --- hw/scsi-disk.c | 10 +--------- 1 files changed, 1 insertions(+), 9 deletions(-) diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c index 5d8bf53..11cfe73 100644 --- a/hw/scsi-disk.c +++ b/hw/scsi-disk.c @@ -391,9 +391,6 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf) } l = strlen(s->serial); - if (l > req->cmd.xfer) { - l = req->cmd.xfer; - } if (l > 20) { l = 20; } @@ -1002,9 +999,6 @@ static int scsi_disk_emulate_mode_sense(SCSIDiskReq *r, uint8_t *outbuf) outbuf[0] = ((buflen - 2) >> 8) & 0xff; outbuf[1] = (buflen - 2) & 0xff; } - if (buflen > r->req.cmd.xfer) { - buflen = r->req.cmd.xfer; - } return buflen; } @@ -1038,9 +1032,6 @@ static int scsi_disk_emulate_read_toc(SCSIRequest *req, uint8_t *outbuf) default: return -1; } - if (toclen > req->cmd.xfer) { - toclen = req->cmd.xfer; - } return toclen; } @@ -1251,6 +1242,7 @@ static int scsi_disk_emulate_command(SCSIDiskReq *r) scsi_check_condition(r, SENSE_CODE(INVALID_OPCODE)); return -1; } + buflen = MIN(buflen, req->cmd.xfer); return buflen; not_ready: -- 1.7.6.5