highperfocused/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

lavc/bmp: Avoid a heap buffer overwrite for 1bpp input.

Browse Source 
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>
This commit is contained in:
Carl Eugen Hoyos 2019-03-26 13:32:11 +01:00 committed by Michael Niedermayer
parent 65f94b732a
commit daca529112
1 changed files with 4 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
libavcodec/bmp.c
View File

@ -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;
}