From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53220) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gHQQB-0000oI-CG for qemu-devel@nongnu.org; Tue, 30 Oct 2018 05:34:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gHQQ7-0003zk-A5 for qemu-devel@nongnu.org; Tue, 30 Oct 2018 05:34:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50999) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gHQQ7-0003wl-3h for qemu-devel@nongnu.org; Tue, 30 Oct 2018 05:34:43 -0400 From: P J P Date: Tue, 30 Oct 2018 15:02:32 +0530 Message-Id: <20181030093232.15660-1-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH v3] lsi53c895a: check message length value is valid List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: Paolo Bonzini , Peter Maydell , Thomas Huth , Fam Zheng , Ameya More , 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. Signed-off-by: Prasad J Pandit --- hw/scsi/lsi53c895a.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) Update v3: modify assert to say s->msg_len > 0 -> https://lists.gnu.org/archive/html/qemu-devel/2018-10/msg06392.html diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c index d1e6534311..3f207f607c 100644 --- a/hw/scsi/lsi53c895a.c +++ b/hw/scsi/lsi53c895a.c @@ -861,10 +861,11 @@ 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; + assert(len > 0 && len <= LSI_MAX_MSGIN_LEN); if (len > s->dbc) len = s->dbc; pci_dma_write(PCI_DEVICE(s), s->dnad, s->msg, len); @@ -1705,8 +1706,10 @@ static uint8_t lsi_reg_readb(LSIState *s, int offset) break; case 0x58: /* SBDL */ /* Some drivers peek at the data bus during the MSG IN phase. */ - if ((s->sstat1 & PHASE_MASK) == PHASE_MI) + if ((s->sstat1 & PHASE_MASK) == PHASE_MI) { + assert(s->msg_len > 0); return s->msg[0]; + } ret = 0; break; case 0x59: /* SBDL high */ @@ -2103,11 +2106,23 @@ static int lsi_pre_save(void *opaque) return 0; } +static int lsi_post_load(void *opaque, int version_id) +{ + LSIState *s = opaque; + + if (s->msg_len < 0 || s->msg_len > LSI_MAX_MSGIN_LEN) { + return -EINVAL; + } + + return 0; +} + static const VMStateDescription vmstate_lsi_scsi = { .name = "lsiscsi", .version_id = 0, .minimum_version_id = 0, .pre_save = lsi_pre_save, + .post_load = lsi_post_load, .fields = (VMStateField[]) { VMSTATE_PCI_DEVICE(parent_obj, LSIState), -- 2.17.2