libtags: id3v2: make sure extra id3 tag does not cause infinite loop

This commit is contained in:
Sigrid Solveig Haflínudóttir 2022-03-30 20:28:03 +00:00
parent f05b8af71e
commit 7f2e622965

View file

@ -366,6 +366,7 @@ tagid3v2(Tagctx *ctx)
{
int sz, exsz, framesz;
int ver, unsync, offset;
int oldpos, newpos;
uchar d[10], *b;
if(ctx->read(ctx, d, sizeof(d)) != sizeof(d))
@ -378,6 +379,7 @@ tagid3v2(Tagctx *ctx)
return 0;
}
oldpos = 0;
header:
ver = d[3];
unsync = d[5] & (1<<7);
@ -449,12 +451,14 @@ header:
if(ctx->read(ctx, ctx->buf, sz) != sz)
break;
for(b = (uchar*)ctx->buf; (b = memchr(b, 'I', sz - 1 - ((char*)b - ctx->buf))) != nil; b++){
ctx->seek(ctx, (char*)b - ctx->buf + offset + exsz, 0);
newpos = ctx->seek(ctx, (char*)b - ctx->buf + offset + exsz, 0);
if(ctx->read(ctx, d, sizeof(d)) != sizeof(d))
return 0;
if(isid3(d))
if(isid3(d) && newpos != oldpos){
oldpos = newpos;
goto header;
}
}
for(b = (uchar*)ctx->buf; (b = memchr(b, 0xff, sz-3)) != nil; b++){
if((b[1] & 0xe0) == 0xe0){
offset = ctx->seek(ctx, (char*)b - ctx->buf + offset + exsz, 0);