Hi Prasad, On 200514 0055, P J P wrote: > From: Prasad J Pandit <p...@fedoraproject.org> > > 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 <rd...@gatech.edu> > Reported-by: Hanqing Zhao <hanq...@gatech.edu> > Reported-by: Alexander Bulekov <alx...@bu.edu> > Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> > ---
Acked-by: Alexander Bulekov <alx...@bu.edu> I applied these patches and could not reproduce the heap-overflow, or LP1878259 Thanks -Alex > hw/scsi/megasas.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > Update v1 -> v2: fix OOB access when index > MEGASAS_MAX_FRAMES(=2048) > -> https://lists.gnu.org/archive/html/qemu-devel/2020-05/msg03131.html > > diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c > index af18c88b65..6ce598cd69 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; > -- > 2.25.4 >