diff options
| author | Mike DePaulo <mikedep333@gmail.com> | 2015-02-08 22:38:32 -0500 |
|---|---|---|
| committer | Mike Gabriel <mike.gabriel@das-netzwerkteam.de> | 2015-02-14 16:14:31 +0100 |
| commit | b65259bf3bcca15b5069cb7a6c06f95a40f79813 (patch) | |
| tree | 41335bc09948cb72fbd76dcdd2f9919ce965c53c | |
| parent | ef439da38d3a4c00a4e03e7d8f83cb359cd9a230 (diff) | |
| download | nx-libs-b65259bf3bcca15b5069cb7a6c06f95a40f79813.tar.gz nx-libs-b65259bf3bcca15b5069cb7a6c06f95a40f79813.tar.bz2 nx-libs-b65259bf3bcca15b5069cb7a6c06f95a40f79813.zip | |
CVE-2014-0210: unvalidated length fields in fs_read_list_info() from xorg/lib/libXfont commit d338f81df1e188eb16e1d6aeea7f4800f89c1218
fs_read_list_info() parses a reply from the font server. The reply
contains a number of additional data items with embedded length or
count fields, none of which are validated. This can cause out of
bound reads when looping over these items in the reply.
| -rw-r--r-- | nx-X11/lib/font/fc/fserve.c | 56 |
1 files changed, 55 insertions, 1 deletions
diff --git a/nx-X11/lib/font/fc/fserve.c b/nx-X11/lib/font/fc/fserve.c index 60d901798..6ba3ad49f 100644 --- a/nx-X11/lib/font/fc/fserve.c +++ b/nx-X11/lib/font/fc/fserve.c @@ -2500,6 +2500,7 @@ fs_read_list_info(FontPathElementPtr fpe, FSBlockDataPtr blockrec) FSBlockedListInfoPtr binfo = (FSBlockedListInfoPtr) blockrec->data; fsListFontsWithXInfoReply *rep; char *buf; + long bufleft; FSFpePtr conn = (FSFpePtr) fpe->private; fsPropInfo *pi; fsPropOffset *po; @@ -2536,7 +2537,8 @@ fs_read_list_info(FontPathElementPtr fpe, FSBlockDataPtr blockrec) } buf = (char *) rep + SIZEOF (fsListFontsWithXInfoReply); - + bufleft = (rep->length << 2) - SIZEOF (fsListFontsWithXInfoReply); + /* * The original FS implementation didn't match * the spec, version 1 was respecified to match the FS. @@ -2544,19 +2546,71 @@ fs_read_list_info(FontPathElementPtr fpe, FSBlockDataPtr blockrec) */ if (conn->fsMajorVersion <= 1) { + if (rep->nameLength > bufleft) { +#ifdef DEBUG + fprintf(stderr, + "fsListFontsWithXInfo: name length (%d) > bufleft (%ld)\n", + (int) rep->nameLength, bufleft); +#endif + err = AllocError; + goto done; + } + /* binfo->name is a 256 char array, rep->nameLength is a CARD8 */ memcpy (binfo->name, buf, rep->nameLength); buf += _fs_pad_length (rep->nameLength); + bufleft -= _fs_pad_length (rep->nameLength); } pi = (fsPropInfo *) buf; + if (SIZEOF (fsPropInfo) > bufleft) { +#ifdef DEBUG + fprintf(stderr, + "fsListFontsWithXInfo: PropInfo length (%d) > bufleft (%ld)\n", + (int) SIZEOF (fsPropInfo), bufleft); +#endif + err = AllocError; + goto done; + } + bufleft -= SIZEOF (fsPropInfo); buf += SIZEOF (fsPropInfo); po = (fsPropOffset *) buf; + if (pi->num_offsets > (bufleft / SIZEOF (fsPropOffset))) { +#ifdef DEBUG + fprintf(stderr, + "fsListFontsWithXInfo: offset length (%d * %d) > bufleft (%ld)\n", + pi->num_offsets, (int) SIZEOF (fsPropOffset), bufleft); +#endif + err = AllocError; + goto done; + } + bufleft -= pi->num_offsets * SIZEOF (fsPropOffset); buf += pi->num_offsets * SIZEOF (fsPropOffset); pd = (pointer) buf; + if (pi->data_len > bufleft) { +#ifdef DEBUG + fprintf(stderr, + "fsListFontsWithXInfo: data length (%d) > bufleft (%ld)\n", + pi->data_len, bufleft); +#endif + err = AllocError; + goto done; + } + bufleft -= pi->data_len; buf += pi->data_len; if (conn->fsMajorVersion > 1) { + if (rep->nameLength > bufleft) { +#ifdef DEBUG + fprintf(stderr, + "fsListFontsWithXInfo: name length (%d) > bufleft (%ld)\n", + (int) rep->nameLength, bufleft); +#endif + err = AllocError; + goto done; + } + /* binfo->name is a 256 char array, rep->nameLength is a CARD8 */ memcpy (binfo->name, buf, rep->nameLength); buf += _fs_pad_length (rep->nameLength); + bufleft -= _fs_pad_length (rep->nameLength); } #ifdef DEBUG |