On 5/11/17, Michael Niedermayer <mich...@niedermayer.cc> wrote: > Most of these were found through code review in response to > fixing 1466/clusterfuzz-testcase-minimized-5961584419536896 > There is thus no testcase for most of this. > The initial issue was Found-by: continuous fuzzing process > https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg > > Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > --- > libavcodec/xpmdec.c | 37 ++++++++++++++++++++++++++++++------- > 1 file changed, 30 insertions(+), 7 deletions(-) > > diff --git a/libavcodec/xpmdec.c b/libavcodec/xpmdec.c > index 9112d4cb5e..03172e4aad 100644 > --- a/libavcodec/xpmdec.c > +++ b/libavcodec/xpmdec.c > @@ -29,6 +29,8 @@ > typedef struct XPMContext { > uint32_t *pixels; > int pixels_size; > + uint8_t *buf; > + int buf_size; > } XPMDecContext; > > typedef struct ColorEntry { > @@ -233,6 +235,8 @@ static uint32_t color_string_to_rgba(const char *p, int > len) > const ColorEntry *entry; > char color_name[100]; > > + len = FFMIN(FFMAX(len, 0), sizeof(color_name) - 1); > + > if (*p == '#') { > p++; > len--; > @@ -299,18 +303,25 @@ static int xpm_decode_frame(AVCodecContext *avctx, > void *data, > { > XPMDecContext *x = avctx->priv_data; > AVFrame *p=data; > - const uint8_t *end, *ptr = avpkt->data; > + const uint8_t *end, *ptr; > int ncolors, cpp, ret, i, j; > int64_t size; > uint32_t *dst; > > avctx->pix_fmt = AV_PIX_FMT_BGRA; > > - end = avpkt->data + avpkt->size; > - while (memcmp(ptr, "/* XPM */", 9) && ptr < end - 9) > + av_fast_padded_malloc(&x->buf, &x->buf_size, avpkt->size); > + if (!x->buf) > + return AVERROR(ENOMEM); > + memcpy(x->buf, avpkt->data, avpkt->size); > + x->buf[avpkt->size] = 0; > + > + ptr = x->buf; > + end = x->buf + avpkt->size; > + while (end - ptr > 9 && memcmp(ptr, "/* XPM */", 9)) > ptr++; > > - if (ptr >= end) { > + if (end - ptr <= 9) { > av_log(avctx, AV_LOG_ERROR, "missing signature\n"); > return AVERROR_INVALIDDATA; > } > @@ -335,7 +346,7 @@ static int xpm_decode_frame(AVCodecContext *avctx, void > *data, > > size = 1; > for (i = 0; i < cpp; i++) > - size *= 94; > + size *= 95; > > if (ncolors <= 0 || ncolors > size) { > av_log(avctx, AV_LOG_ERROR, "invalid number of colors: %d\n", > ncolors); > @@ -349,12 +360,15 @@ static int xpm_decode_frame(AVCodecContext *avctx, > void *data, > return AVERROR(ENOMEM); > > ptr += mod_strcspn(ptr, ",") + 1; > + if (end - ptr < 1) > + return AVERROR_INVALIDDATA; > + > for (i = 0; i < ncolors; i++) { > const uint8_t *index; > int len; > > ptr += mod_strcspn(ptr, "\"") + 1; > - if (ptr + cpp > end) > + if (end - ptr < cpp) > return AVERROR_INVALIDDATA; > index = ptr; > ptr += cpp; > @@ -373,14 +387,20 @@ static int xpm_decode_frame(AVCodecContext *avctx, > void *data, > > x->pixels[ret] = color_string_to_rgba(ptr, len); > ptr += mod_strcspn(ptr, ",") + 1; > + if (end - ptr < 1) > + return AVERROR_INVALIDDATA; > } > > for (i = 0; i < avctx->height; i++) { > dst = (uint32_t *)(p->data[0] + i * p->linesize[0]); > + if (end - ptr < 1) > + return AVERROR_INVALIDDATA; > ptr += mod_strcspn(ptr, "\"") + 1; > + if (end - ptr < 1) > + return AVERROR_INVALIDDATA; > > for (j = 0; j < avctx->width; j++) { > - if (ptr + cpp > end) > + if (end - ptr < cpp) > return AVERROR_INVALIDDATA; > > if ((ret = ascii2index(ptr, cpp)) < 0) > @@ -405,6 +425,9 @@ static av_cold int xpm_decode_close(AVCodecContext > *avctx) > XPMDecContext *x = avctx->priv_data; > av_freep(&x->pixels); > > + av_freep(&x->buf); > + x->buf_size = 0; > + > return 0; > } > > -- > 2.11.0 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel >
This is suboptimal solution. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
