From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39626) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gFm1v-0001Vp-7c for qemu-devel@nongnu.org; Thu, 25 Oct 2018 16:15:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gFlz0-00058w-Ad for qemu-devel@nongnu.org; Thu, 25 Oct 2018 16:11:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38986) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gFlz0-00056g-4t for qemu-devel@nongnu.org; Thu, 25 Oct 2018 16:11:54 -0400 From: P J P Date: Fri, 26 Oct 2018 01:39:44 +0530 Message-Id: <20181025200944.12113-1-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH] lsi53c895a: check message length value List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: Ameya More , Paolo Bonzini , Fam Zheng , Prasad J Pandit From: Prasad J Pandit While writing a message in 'lsi_do_msgin', message length value in msg_len could be invalid, add check to avoid OOB access issue. Reported-by: Ameya More Signed-off-by: Prasad J Pandit --- hw/scsi/lsi53c895a.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c index d1e6534311..a266c5a113 100644 --- a/hw/scsi/lsi53c895a.c +++ b/hw/scsi/lsi53c895a.c @@ -205,7 +205,7 @@ typedef struct { /* Action to take at the end of a MSG IN phase. 0 = COMMAND, 1 = disconnect, 2 = DATA OUT, 3 = DATA IN. */ int msg_action; - int msg_len; + uint8_t msg_len; uint8_t msg[LSI_MAX_MSGIN_LEN]; /* 0 if SCRIPTS are running or stopped. * 1 if a Wait Reselect instruction has been issued. @@ -861,12 +861,15 @@ static void lsi_do_status(LSIState *s) static void lsi_do_msgin(LSIState *s) { - int len; + uint8_t len; trace_lsi_do_msgin(s->dbc, s->msg_len); s->sfbr = s->msg[0]; len = s->msg_len; if (len > s->dbc) len = s->dbc; + if (len > LSI_MAX_MSGIN_LEN) { + len = LSI_MAX_MSGIN_LEN; + } pci_dma_write(PCI_DEVICE(s), s->dnad, s->msg, len); /* Linux drivers rely on the last byte being in the SIDL. */ s->sidl = s->msg[len - 1]; @@ -2114,7 +2117,7 @@ static const VMStateDescription vmstate_lsi_scsi = { VMSTATE_INT32(carry, LSIState), VMSTATE_INT32(status, LSIState), VMSTATE_INT32(msg_action, LSIState), - VMSTATE_INT32(msg_len, LSIState), + VMSTATE_UINT8(msg_len, LSIState), VMSTATE_BUFFER(msg, LSIState), VMSTATE_INT32(waiting, LSIState), -- 2.17.2