Commit e081fb10 authored by Prasad J Pandit's avatar Prasad J Pandit Committed by zhanghailiang
Browse files

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: default avatarRen Ding <rding@gatech.edu>
Reported-by: default avatarHanqing Zhao <hanqing@gatech.edu>
Reported-by: default avatarAlexander Bulekov <alxndr@bu.edu>
Signed-off-by: default avatarPrasad J Pandit <pjp@fedoraproject.org>
Acked-by: default avatarAlexander Bulekov <alxndr@bu.edu>
Message-Id: <20200513192540.1583887-2-ppandit@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 89554d2f

hw/scsi/megasas.c

+2 −2
Original line number Diff line number Diff line
@@ -111,7 +111,7 @@ 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;
@@ -444,7 +444,7 @@ 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;