From: José Aliste Date: Tue, 7 Dec 2010 18:56:47 +0000 (-0300) Subject: backends: Fix several security issues in the dvi-backend. X-Git-Tag: EVINCE_2_91_5~11 X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=commitdiff_plain;h=d4139205b010ed06310d14284e63114e88ec6de2;p=evince.git backends: Fix several security issues in the dvi-backend. See CVE-2010-2640, CVE-2010-2641, CVE-2010-2642 and CVE-2010-2643. --- diff --git a/backend/dvi/mdvi-lib/afmparse.c b/backend/dvi/mdvi-lib/afmparse.c index 164366b0..361e23d6 100644 --- a/backend/dvi/mdvi-lib/afmparse.c +++ b/backend/dvi/mdvi-lib/afmparse.c @@ -160,7 +160,7 @@ static char *token(FILE *stream) idx = 0; while (ch != EOF && ch != ' ' && ch != lineterm - && ch != '\t' && ch != ':' && ch != ';') + && ch != '\t' && ch != ':' && ch != ';' && idx < MAX_NAME) { ident[idx++] = ch; ch = fgetc(stream); diff --git a/backend/dvi/mdvi-lib/dviread.c b/backend/dvi/mdvi-lib/dviread.c index cd8cfa91..d0143205 100644 --- a/backend/dvi/mdvi-lib/dviread.c +++ b/backend/dvi/mdvi-lib/dviread.c @@ -1507,6 +1507,10 @@ int special(DviContext *dvi, int opcode) Int32 arg; arg = dugetn(dvi, opcode - DVI_XXX1 + 1); + if (arg <= 0) { + dvierr(dvi, _("malformed special length\n")); + return -1; + } s = mdvi_malloc(arg + 1); dread(dvi, s, arg); s[arg] = 0; diff --git a/backend/dvi/mdvi-lib/pk.c b/backend/dvi/mdvi-lib/pk.c index a5791869..08377e63 100644 --- a/backend/dvi/mdvi-lib/pk.c +++ b/backend/dvi/mdvi-lib/pk.c @@ -469,6 +469,15 @@ static int pk_load_font(DviParams *unused, DviFont *font) } if(feof(p)) break; + + /* Although the PK format support bigger char codes, + * XeTeX and other extended TeX engines support charcodes up to + * 65536, while normal TeX engine supports only charcode up to 255.*/ + if (cc < 0 || cc > 65536) { + mdvi_error (_("%s: unexpected charcode (%d)\n"), + font->fontname,cc); + goto error; + } if(cc < loc) loc = cc; if(cc > hic) @@ -512,7 +521,7 @@ static int pk_load_font(DviParams *unused, DviFont *font) } /* resize font char data */ - if(loc > 0 || hic < maxch-1) { + if(loc > 0 && hic < maxch-1) { memmove(font->chars, font->chars + loc, (hic - loc + 1) * sizeof(DviFontChar)); font->chars = xresize(font->chars, diff --git a/backend/dvi/mdvi-lib/tfmfile.c b/backend/dvi/mdvi-lib/tfmfile.c index 73ebf26a..8c2a30b2 100644 --- a/backend/dvi/mdvi-lib/tfmfile.c +++ b/backend/dvi/mdvi-lib/tfmfile.c @@ -172,7 +172,8 @@ int tfm_load_file(const char *filename, TFMInfo *info) /* We read the entire TFM file into core */ if(fstat(fileno(in), &st) < 0) return -1; - if(st.st_size == 0) + /* according to the spec, TFM files are smaller than 16K */ + if(st.st_size == 0 || st.st_size >= 16384) goto bad_tfm; /* allocate a word-aligned buffer to hold the file */ diff --git a/backend/dvi/mdvi-lib/vf.c b/backend/dvi/mdvi-lib/vf.c index fb498476..a5ae3bbe 100644 --- a/backend/dvi/mdvi-lib/vf.c +++ b/backend/dvi/mdvi-lib/vf.c @@ -165,6 +165,12 @@ static int vf_load_font(DviParams *params, DviFont *font) cc = fuget1(p); tfm = fuget3(p); } + if (cc < 0 || cc > 65536) { + /* TeX engines do not support char codes bigger than 65535 */ + mdvi_error(_("(vf) %s: unexpected character %d\n"), + font->fontname, cc); + goto error; + } if(loc < 0 || cc < loc) loc = cc; if(hic < 0 || cc > hic)