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| author | Tatsuya Kinoshita <tats@debian.org> | 2016-12-10 09:10:10 +0000 |
|---|---|---|
| committer | Tatsuya Kinoshita <tats@debian.org> | 2016-12-10 13:09:34 +0000 |
| commit | 998b6f91d4b02e8bf90b7744dfabc8cccdf9d4f9 (patch) | |
| tree | 7abb8918ed9b12d0d5135f521dee37187bd79279 | |
| parent | Prevent heap-buffer-overflow in Strnew_size() (diff) | |
| download | w3m-998b6f91d4b02e8bf90b7744dfabc8cccdf9d4f9.tar.gz w3m-998b6f91d4b02e8bf90b7744dfabc8cccdf9d4f9.zip | |
Prevent overflow beyond the end of string in wtf_parse1()
Bug-Debian: https://github.com/tats/w3m/issues/68
| -rw-r--r-- | libwc/wtf.c | 42 |
1 files changed, 24 insertions, 18 deletions
diff --git a/libwc/wtf.c b/libwc/wtf.c index bf87e5f..9a9a15c 100644 --- a/libwc/wtf.c +++ b/libwc/wtf.c @@ -391,45 +391,51 @@ wtf_parse1(wc_uchar **p) cc.code = *(q++); } else if (*q > 0xa0) { cc.ccs = wtf_gr_ccs; - if (WC_CCS_IS_WIDE(cc.ccs)) { + if (WC_CCS_IS_WIDE(cc.ccs) && *(q+1)) { cc.code = ((wc_uint32)*q << 8) | *(q+1); q += 2; } else cc.code = *(q++); } else { - cc.ccs = (wc_uint32)CCS_MAP[*(q++) - 0x80] << 8; + cc.ccs = WC_CCS_US_ASCII; + cc.code = (wc_uint32)' '; + if (*q) + cc.ccs = (wc_uint32)CCS_MAP[*(q++) - 0x80] << 8; switch (WC_CCS_TYPE(cc.ccs)) { case WC_CCS_A_CS94: case WC_CCS_A_CS96: case WC_CCS_A_CS942: case WC_CCS_A_PCS: case WC_CCS_A_UNKNOWN: - cc.ccs |= *(q++) & 0x7f; - cc.code = *(q++); + if (*q && *(q+1)) { + cc.ccs |= *(q++) & 0x7f; + cc.code = *(q++); + } break; case WC_CCS_A_CS94W: case WC_CCS_A_CS96W: case WC_CCS_A_PCSW: - cc.ccs |= *(q++) & 0x7f; - cc.code = ((wc_uint32)*q << 8) | *(q+1); - q += 2; + if (*q && *(q+1) && *(q+2)) { + cc.ccs |= *(q++) & 0x7f; + cc.code = ((wc_uint32)*q << 8) | *(q+1); + q += 2; + } break; case WC_CCS_A_WCS16: case WC_CCS_A_WCS16W: - cc.ccs |= (*q & 0x7c) >> 2; - cc.code = wtf_to_wcs16(q); - q += 3; + if (*q && *(q+1) && *(q+2)) { + cc.ccs |= (*q & 0x7c) >> 2; + cc.code = wtf_to_wcs16(q); + q += 3; + } break; case WC_CCS_A_WCS32: case WC_CCS_A_WCS32W: - cc.ccs |= (*q & 0x70) >> 4; - cc.code = wtf_to_wcs32(q); - q += 5; - break; - default: - /* case 0: */ - cc.ccs = WC_CCS_US_ASCII; - cc.code = (wc_uint32)' '; + if (*q && *(q+1) && *(q+2) && *(q+3) && *(q+4)) { + cc.ccs |= (*q & 0x70) >> 4; + cc.code = wtf_to_wcs32(q); + q += 5; + } break; } } |