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es1370: check total frame count against current frame

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A guest user may set channel frame count via es1370_write()
such that, in es1370_transfer_audio(), total frame count
'size' is lesser than the number of frames that are processed
'cnt'.

    int cnt = d->frame_cnt >> 16;
    int size = d->frame_cnt & 0xffff;

if (size < cnt), it results in incorrect calculations leading
to OOB access issue(s). Add check to avoid it.

Reported-by: Ren Ding <rding@gatech.edu>
Reported-by: Hanqing Zhao <hanqing@gatech.edu>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-id: 20200514200608.1744203-1-ppandit@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Prasad J Pandit 2020-05-15 01:36:08 +05:30 committed by Gerd Hoffmann
parent fea8f3ed73
commit 369ff955a8
1 changed files with 5 additions and 2 deletions
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7
hw/audio/es1370.c
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@ -643,6 +643,9 @@ static void es1370_transfer_audio (ES1370State *s, struct chan *d, int loop_sel,
int csc_bytes = (csc + 1) << d->shift;
int cnt = d->frame_cnt >> 16;
int size = d->frame_cnt & 0xffff;
if (size < cnt) {
return;
}
int left = ((size - cnt + 1) << 2) + d->leftover;
int transferred = 0;
int temp = MIN (max, MIN (left, csc_bytes));
@ -651,7 +654,7 @@ static void es1370_transfer_audio (ES1370State *s, struct chan *d, int loop_sel,
addr += (cnt << 2) + d->leftover;
if (index == ADC_CHANNEL) {
while (temp) {
while (temp > 0) {
int acquired, to_copy;
to_copy = MIN ((size_t) temp, sizeof (tmpbuf));
@ -669,7 +672,7 @@ static void es1370_transfer_audio (ES1370State *s, struct chan *d, int loop_sel,
else {
SWVoiceOut *voice = s->dac_voice[index];
while (temp) {
while (temp > 0) {
int copied, to_copy;
to_copy = MIN ((size_t) temp, sizeof (tmpbuf));