shorten: Use separate pointers for the allocated memory for decoded samples.

Fixes invalid free() if any of the buffers are not allocated due to either
not decoding a header or an error prior to allocating all buffers.

Fixes CVE-2012-0858
CC: libav-stable@libav.org

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>
This commit is contained in:
Michael Niedermayer 2011-12-25 12:28:50 +01:00 committed by Justin Ruggles
parent c509f4f747
commit 204cb29b3c

View File

@ -86,6 +86,7 @@ typedef struct ShortenContext {
int channels;
int32_t *decoded[MAX_CHANNELS];
int32_t *decoded_base[MAX_CHANNELS];
int32_t *offset[MAX_CHANNELS];
int *coeffs;
uint8_t *bitstream;
@ -140,13 +141,14 @@ static int allocate_buffers(ShortenContext *s)
return AVERROR(ENOMEM);
s->offset[chan] = tmp_ptr;
tmp_ptr = av_realloc(s->decoded[chan], sizeof(int32_t)*(s->blocksize + s->nwrap));
tmp_ptr = av_realloc(s->decoded_base[chan], (s->blocksize + s->nwrap) *
sizeof(s->decoded_base[0][0]));
if (!tmp_ptr)
return AVERROR(ENOMEM);
s->decoded[chan] = tmp_ptr;
s->decoded_base[chan] = tmp_ptr;
for (i=0; i<s->nwrap; i++)
s->decoded[chan][i] = 0;
s->decoded[chan] += s->nwrap;
s->decoded_base[chan][i] = 0;
s->decoded[chan] = s->decoded_base[chan] + s->nwrap;
}
coeffs = av_realloc(s->coeffs, s->nwrap * sizeof(*s->coeffs));
@ -615,8 +617,8 @@ static av_cold int shorten_decode_close(AVCodecContext *avctx)
int i;
for (i = 0; i < s->channels; i++) {
s->decoded[i] -= s->nwrap;
av_freep(&s->decoded[i]);
s->decoded[i] = NULL;
av_freep(&s->decoded_base[i]);
av_freep(&s->offset[i]);
}
av_freep(&s->bitstream);