From f50ab86a2620bd7e8507af865b164655ee921661 Mon Sep 17 00:00:00 2001 From: Prasad J Pandit Date: Thu, 14 May 2020 00:55:38 +0530 Subject: [PATCH] megasas: use unsigned type for reply_queue_head and check index A guest user may set 'reply_queue_head' field of MegasasState to a negative value. Later in 'megasas_lookup_frame' it is used to index into s->frames[] array. Use unsigned type to avoid OOB access issue. Also check that 'index' value stays within s->frames[] bounds through the while() loop in 'megasas_lookup_frame' to avoid OOB access. Reported-by: Ren Ding Reported-by: Hanqing Zhao Reported-by: Alexander Bulekov Signed-off-by: Prasad J Pandit Acked-by: Alexander Bulekov Message-Id: <20200513192540.1583887-2-ppandit@redhat.com> Signed-off-by: Paolo Bonzini Upstream-Status: Backport [https://git.qemu.org/?p=qemu.git;a=commit;h=f50ab86a2620bd7e8507af865b164655ee921661] CVE: CVE-2020-13362 Signed-off-by: Chee Yang Lee --- hw/scsi/megasas.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c index af18c88b656..6ce598cd690 100644 --- a/hw/scsi/megasas.c +++ b/hw/scsi/megasas.c @@ -112,7 +112,7 @@ typedef struct MegasasState { uint64_t reply_queue_pa; void *reply_queue; int reply_queue_len; - int reply_queue_head; + uint16_t reply_queue_head; int reply_queue_tail; uint64_t consumer_pa; uint64_t producer_pa; @@ -445,7 +445,7 @@ static MegasasCmd *megasas_lookup_frame(MegasasState *s, index = s->reply_queue_head; - while (num < s->fw_cmds) { + while (num < s->fw_cmds && index < MEGASAS_MAX_FRAMES) { if (s->frames[index].pa && s->frames[index].pa == frame) { cmd = &s->frames[index]; break;