$NetBSD: patch-src_fc_fserve.c,v 1.2.2.2 2014/05/21 13:14:03 tron Exp $ --- src/fc/fserve.c.orig 2014-01-07 16:25:08.000000000 +0000 +++ src/fc/fserve.c @@ -70,6 +70,7 @@ in this Software without prior written a #include "fservestr.h" #include #include +#include #include #define Time_t time_t @@ -91,6 +92,15 @@ in this Software without prior written a (pci)->descent || \ (pci)->characterWidth) +/* + * SIZEOF(r) is in bytes, length fields in the protocol are in 32-bit words, + * so this converts for doing size comparisons. + */ +#define LENGTHOF(r) (SIZEOF(r) >> 2) + +/* Somewhat arbitrary limit on maximum reply size we'll try to read. */ +#define MAX_REPLY_LENGTH ((64 * 1024 * 1024) >> 2) + extern void ErrorF(const char *f, ...); static int fs_read_glyphs ( FontPathElementPtr fpe, FSBlockDataPtr blockrec ); @@ -206,9 +216,22 @@ _fs_add_rep_log (FSFpePtr conn, fsGeneri rep->sequenceNumber, conn->reqbuffer[i].opcode); } + +#define _fs_reply_failed(rep, name, op) do { \ + if (rep) { \ + if (rep->type == FS_Error) \ + fprintf (stderr, "Error: %d Request: %s\n", \ + ((fsError *)rep)->request, #name); \ + else \ + fprintf (stderr, "Bad Length for %s Reply: %d %s %d\n", \ + #name, rep->length, op, LENGTHOF(name)); \ + } \ +} while (0) + #else #define _fs_add_req_log(conn,op) ((conn)->current_seq++) #define _fs_add_rep_log(conn,rep) +#define _fs_reply_failed(rep,name,op) #endif static Bool @@ -600,6 +623,21 @@ fs_get_reply (FSFpePtr conn, int *error) rep = (fsGenericReply *) buf; + /* + * Refuse to accept replies longer than a maximum reasonable length, + * before we pass to _fs_start_read, since it will try to resize the + * incoming connection buffer to this size. Also avoids integer overflow + * on 32-bit systems. + */ + if (rep->length > MAX_REPLY_LENGTH) + { + ErrorF("fserve: reply length %d > MAX_REPLY_LENGTH, disconnecting" + " from font server\n", rep->length); + _fs_connection_died (conn); + *error = FSIO_ERROR; + return 0; + } + ret = _fs_start_read (conn, rep->length << 2, &buf); if (ret != FSIO_READY) { @@ -682,13 +720,15 @@ fs_read_open_font(FontPathElementPtr fpe int ret; rep = (fsOpenBitmapFontReply *) fs_get_reply (conn, &ret); - if (!rep || rep->type == FS_Error) + if (!rep || rep->type == FS_Error || + (rep->length != LENGTHOF(fsOpenBitmapFontReply))) { if (ret == FSIO_BLOCK) return StillWorking; if (rep) _fs_done_read (conn, rep->length << 2); fs_cleanup_bfont (bfont); + _fs_reply_failed (rep, fsOpenBitmapFontReply, "!="); return BadFontName; } @@ -815,6 +855,7 @@ fs_read_query_info(FontPathElementPtr fp FSFpePtr conn = (FSFpePtr) fpe->private; fsQueryXInfoReply *rep; char *buf; + long bufleft; /* length of reply left to use */ fsPropInfo *pi; fsPropOffset *po; pointer pd; @@ -824,13 +865,15 @@ fs_read_query_info(FontPathElementPtr fp int ret; rep = (fsQueryXInfoReply *) fs_get_reply (conn, &ret); - if (!rep || rep->type == FS_Error) + if (!rep || rep->type == FS_Error || + (rep->length < LENGTHOF(fsQueryXInfoReply))) { if (ret == FSIO_BLOCK) return StillWorking; if (rep) _fs_done_read (conn, rep->length << 2); fs_cleanup_bfont (bfont); + _fs_reply_failed (rep, fsQueryXInfoReply, "<"); return BadFontName; } @@ -844,6 +887,9 @@ fs_read_query_info(FontPathElementPtr fp buf = (char *) rep; buf += SIZEOF(fsQueryXInfoReply); + bufleft = rep->length << 2; + bufleft -= SIZEOF(fsQueryXInfoReply); + /* move the data over */ fsUnpack_XFontInfoHeader(rep, pInfo); @@ -851,17 +897,50 @@ fs_read_query_info(FontPathElementPtr fp _fs_init_fontinfo(conn, pInfo); /* Compute offsets into the reply */ + if (bufleft < SIZEOF(fsPropInfo)) + { + ret = -1; +#ifdef DEBUG + fprintf(stderr, "fsQueryXInfo: bufleft (%ld) < SIZEOF(fsPropInfo)\n", + bufleft); +#endif + goto bail; + } pi = (fsPropInfo *) buf; buf += SIZEOF (fsPropInfo); + bufleft -= SIZEOF(fsPropInfo); + if ((bufleft / SIZEOF(fsPropOffset)) < pi->num_offsets) + { + ret = -1; +#ifdef DEBUG + fprintf(stderr, + "fsQueryXInfo: bufleft (%ld) / SIZEOF(fsPropOffset) < %d\n", + bufleft, pi->num_offsets); +#endif + goto bail; + } po = (fsPropOffset *) buf; buf += pi->num_offsets * SIZEOF(fsPropOffset); + bufleft -= pi->num_offsets * SIZEOF(fsPropOffset); + if (bufleft < pi->data_len) + { + ret = -1; +#ifdef DEBUG + fprintf(stderr, + "fsQueryXInfo: bufleft (%ld) < data_len (%d)\n", + bufleft, pi->data_len); +#endif + goto bail; + } pd = (pointer) buf; buf += pi->data_len; + bufleft -= pi->data_len; /* convert the properties and step over the reply */ ret = _fs_convert_props(pi, po, pd, pInfo); + bail: _fs_done_read (conn, rep->length << 2); if (ret == -1) @@ -951,13 +1030,15 @@ fs_read_extent_info(FontPathElementPtr f FontInfoRec *fi = &bfont->pfont->info; rep = (fsQueryXExtents16Reply *) fs_get_reply (conn, &ret); - if (!rep || rep->type == FS_Error) + if (!rep || rep->type == FS_Error || + (rep->length < LENGTHOF(fsQueryXExtents16Reply))) { if (ret == FSIO_BLOCK) return StillWorking; if (rep) _fs_done_read (conn, rep->length << 2); fs_cleanup_bfont (bfont); + _fs_reply_failed (rep, fsQueryXExtents16Reply, "<"); return BadFontName; } @@ -970,7 +1051,26 @@ fs_read_extent_info(FontPathElementPtr f numInfos *= 2; haveInk = TRUE; } - ci = pCI = malloc(sizeof(CharInfoRec) * numInfos); + if (numInfos >= (INT_MAX / sizeof(CharInfoRec))) { +#ifdef DEBUG + fprintf(stderr, + "fsQueryXExtents16: numInfos (%d) >= %ld\n", + numInfos, (INT_MAX / sizeof(CharInfoRec))); +#endif + pCI = NULL; + } + else if (numExtents > ((rep->length - LENGTHOF(fsQueryXExtents16Reply)) + / LENGTHOF(fsXCharInfo))) { +#ifdef DEBUG + fprintf(stderr, + "fsQueryXExtents16: numExtents (%d) > (%d - %d) / %d\n", + numExtents, rep->length, + LENGTHOF(fsQueryXExtents16Reply), LENGTHOF(fsXCharInfo)); +#endif + pCI = NULL; + } + else + pCI = malloc(sizeof(CharInfoRec) * numInfos); if (!pCI) { @@ -1809,6 +1909,7 @@ fs_read_glyphs(FontPathElementPtr fpe, F FontInfoPtr pfi = &pfont->info; fsQueryXBitmaps16Reply *rep; char *buf; + long bufleft; /* length of reply left to use */ fsOffset32 *ppbits; fsOffset32 local_off; char *off_adr; @@ -1825,21 +1926,48 @@ fs_read_glyphs(FontPathElementPtr fpe, F unsigned long minchar, maxchar; rep = (fsQueryXBitmaps16Reply *) fs_get_reply (conn, &ret); - if (!rep || rep->type == FS_Error) + if (!rep || rep->type == FS_Error || + (rep->length < LENGTHOF(fsQueryXBitmaps16Reply))) { if (ret == FSIO_BLOCK) return StillWorking; if (rep) _fs_done_read (conn, rep->length << 2); err = AllocError; + _fs_reply_failed (rep, fsQueryXBitmaps16Reply, "<"); goto bail; } buf = (char *) rep; buf += SIZEOF (fsQueryXBitmaps16Reply); + bufleft = rep->length << 2; + bufleft -= SIZEOF (fsQueryXBitmaps16Reply); + + if ((bufleft / SIZEOF (fsOffset32)) < rep->num_chars) + { +#ifdef DEBUG + fprintf(stderr, + "fsQueryXBitmaps16: num_chars (%d) > bufleft (%ld) / %d\n", + rep->num_chars, bufleft, SIZEOF (fsOffset32)); +#endif + err = AllocError; + goto bail; + } ppbits = (fsOffset32 *) buf; buf += SIZEOF (fsOffset32) * (rep->num_chars); + bufleft -= SIZEOF (fsOffset32) * (rep->num_chars); + + if (bufleft < rep->nbytes) + { +#ifdef DEBUG + fprintf(stderr, + "fsQueryXBitmaps16: nbytes (%d) > bufleft (%ld)\n", + rep->nbytes, bufleft); +#endif + err = AllocError; + goto bail; + } pbitmaps = (pointer ) buf; @@ -1898,7 +2026,9 @@ fs_read_glyphs(FontPathElementPtr fpe, F */ if (NONZEROMETRICS(&fsdata->encoding[minchar].metrics)) { - if (local_off.length) + if (local_off.length && + (local_off.position < rep->nbytes) && + (local_off.length <= (rep->nbytes - local_off.position))) { bits = allbits; allbits += local_off.length; @@ -2228,31 +2358,48 @@ fs_read_list(FontPathElementPtr fpe, FSB FSBlockedListPtr blist = (FSBlockedListPtr) blockrec->data; fsListFontsReply *rep; char *data; + long dataleft; /* length of reply left to use */ int length, i, ret; int err; rep = (fsListFontsReply *) fs_get_reply (conn, &ret); - if (!rep || rep->type == FS_Error) + if (!rep || rep->type == FS_Error || + (rep->length < LENGTHOF(fsListFontsReply))) { if (ret == FSIO_BLOCK) return StillWorking; if (rep) _fs_done_read (conn, rep->length << 2); + _fs_reply_failed (rep, fsListFontsReply, "<"); return AllocError; } data = (char *) rep + SIZEOF (fsListFontsReply); + dataleft = (rep->length << 2) - SIZEOF (fsListFontsReply); err = Successful; /* copy data into FontPathRecord */ for (i = 0; i < rep->nFonts; i++) { + if (dataleft < 1) + break; length = *(unsigned char *)data++; + dataleft--; /* used length byte */ + if (length > dataleft) { +#ifdef DEBUG + fprintf(stderr, + "fsListFonts: name length (%d) > dataleft (%ld)\n", + length, dataleft); +#endif + err = BadFontName; + break; + } err = AddFontNamesName(blist->names, data, length); if (err != Successful) break; data += length; + dataleft -= length; } _fs_done_read (conn, rep->length << 2); return err; @@ -2358,12 +2505,15 @@ fs_read_list_info(FontPathElementPtr fpe _fs_free_props (&binfo->info); rep = (fsListFontsWithXInfoReply *) fs_get_reply (conn, &ret); - if (!rep || rep->type == FS_Error) + if (!rep || rep->type == FS_Error || + ((rep->nameLength != 0) && + (rep->length < LENGTHOF(fsListFontsWithXInfoReply)))) { if (ret == FSIO_BLOCK) return StillWorking; binfo->status = FS_LFWI_FINISHED; err = AllocError; + _fs_reply_failed (rep, fsListFontsWithXInfoReply, "<"); goto done; } /* @@ -2786,7 +2936,7 @@ _fs_recv_conn_setup (FSFpePtr conn) int ret = FSIO_ERROR; fsConnSetup *setup; FSFpeAltPtr alts; - int i, alt_len; + unsigned int i, alt_len; int setup_len; char *alt_save, *alt_names; @@ -2813,8 +2963,9 @@ _fs_recv_conn_setup (FSFpePtr conn) } if (setup->num_alternates) { + size_t alt_name_len = setup->alternate_len << 2; alts = malloc (setup->num_alternates * sizeof (FSFpeAltRec) + - (setup->alternate_len << 2)); + alt_name_len); if (alts) { alt_names = (char *) (setup + 1); @@ -2823,10 +2974,25 @@ _fs_recv_conn_setup (FSFpePtr conn) { alts[i].subset = alt_names[0]; alt_len = alt_names[1]; + if (alt_len >= alt_name_len) { + /* + * Length is longer than setup->alternate_len + * told us to allocate room for, assume entire + * alternate list is corrupted. + */ +#ifdef DEBUG + fprintf (stderr, + "invalid alt list (length %lx >= %lx)\n", + (long) alt_len, (long) alt_name_len); +#endif + free(alts); + return FSIO_ERROR; + } alts[i].name = alt_save; memcpy (alt_save, alt_names + 2, alt_len); alt_save[alt_len] = '\0'; alt_save += alt_len + 1; + alt_name_len -= alt_len + 1; alt_names += _fs_pad_length (alt_len + 2); } conn->numAlts = setup->num_alternates;