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[FFmpeg-devel,3/8] avcodec/mpl2dec: do not overread if zero padding is missing

Message ID 20210313213345.3268-3-cus@passwd.hu
State New
Headers show
Series [FFmpeg-devel,1/8] avcodec/assdec: do not overread if zero padding is missing
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Commit Message

Marton Balint March 13, 2021, 9:33 p.m. UTC
Signed-off-by: Marton Balint <cus@passwd.hu>
---
 libavcodec/mpl2dec.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/libavcodec/mpl2dec.c b/libavcodec/mpl2dec.c
index 409e4b3708..efeecb0d64 100644
--- a/libavcodec/mpl2dec.c
+++ b/libavcodec/mpl2dec.c
@@ -29,15 +29,15 @@ 
 #include "ass.h"
 #include "libavutil/bprint.h"
 
-static int mpl2_event_to_ass(AVBPrint *buf, const char *p)
+static int mpl2_event_to_ass(AVBPrint *buf, const char *p, const char *pend)
 {
     if (*p == ' ')
         p++;
 
-    while (*p) {
+    while (p < pend && *p) {
         int got_style = 0;
 
-        while (*p && strchr("/\\_", *p)) {
+        while (p < pend && *p && strchr("/\\_", *p)) {
             if      (*p == '/')  av_bprintf(buf, "{\\i1}");
             else if (*p == '\\') av_bprintf(buf, "{\\b1}");
             else if (*p == '_')  av_bprintf(buf, "{\\u1}");
@@ -45,13 +45,13 @@  static int mpl2_event_to_ass(AVBPrint *buf, const char *p)
             p++;
         }
 
-        while (*p && *p != '|') {
+        while (p < pend && *p && *p != '|') {
             if (*p != '\r' && *p != '\n')
                 av_bprint_chars(buf, *p, 1);
             p++;
         }
 
-        if (*p == '|') {
+        if (p < pend && *p == '|') {
             if (got_style)
                 av_bprintf(buf, "{\\r}");
             av_bprintf(buf, "\\N");
@@ -72,7 +72,7 @@  static int mpl2_decode_frame(AVCodecContext *avctx, void *data,
     FFASSDecoderContext *s = avctx->priv_data;
 
     av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
-    if (ptr && avpkt->size > 0 && *ptr && !mpl2_event_to_ass(&buf, ptr))
+    if (ptr && avpkt->size > 0 && *ptr && !mpl2_event_to_ass(&buf, ptr, ptr + avpkt->size))
         ret = ff_ass_add_rect(sub, buf.str, s->readorder++, 0, NULL, NULL);
     av_bprint_finalize(&buf, NULL);
     if (ret < 0)