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| author | Carl Eugen Hoyos <ceffmpeg@gmail.com> | 2019-03-26 13:32:11 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-03-27 08:47:30 +0100 |
| commit | d31940f04e864542819fb6b998d796e14305bd3c (patch) | |
| tree | d829d36c667df1077742a4a2e9132b91cc04d3c7 | |
| parent | 807d443c7eb4318c768f2b665c81defa405e9fe2 (diff) | |
| download | ffmpeg-d31940f04e864542819fb6b998d796e14305bd3c.tar.gz | |
lavc/bmp: Avoid a heap buffer overwrite for 1bpp input.
Found by Mingi Cho, Seoyoung Kim, and Taekyoung Kwon
of the Information Security Lab, Yonsei University.
(cherry picked from commit 1e34014010dba9325fc5430934b51a61a5007c63)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/bmp.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/libavcodec/bmp.c b/libavcodec/bmp.c index 65d239e4f8..40010ac46f 100644 --- a/libavcodec/bmp.c +++ b/libavcodec/bmp.c @@ -291,7 +291,7 @@ static int bmp_decode_frame(AVCodecContext *avctx, case 1: for (i = 0; i < avctx->height; i++) { int j; - for (j = 0; j < n; j++) { + for (j = 0; j < avctx->width >> 3; j++) { ptr[j*8+0] = buf[j] >> 7; ptr[j*8+1] = (buf[j] >> 6) & 1; ptr[j*8+2] = (buf[j] >> 5) & 1; @@ -301,6 +301,9 @@ static int bmp_decode_frame(AVCodecContext *avctx, ptr[j*8+6] = (buf[j] >> 1) & 1; ptr[j*8+7] = buf[j] & 1; } + for (j = 0; j < (avctx->width & 7); j++) { + ptr[avctx->width - (avctx->width & 7) + j] = buf[avctx->width >> 3] >> (7 - j) & 1; + } buf += n; ptr += linesize; } |