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| author | Paul Eggert <eggert@cs.ucla.edu> | 2021-11-24 14:16:09 -0800 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2021-11-24 14:16:09 -0800 |
| commit | c52ef24829f95a819965214eeae28e3289a91a61 (patch) | |
| tree | a6b392f79ecdf87f3c0bbe299b19ab6cab414dcc | |
| parent | c58d3b7d00d5b4295dfb884b38f3e5945227fa01 (diff) | |
| download | glibc-c52ef24829f95a819965214eeae28e3289a91a61.tar.gz glibc-c52ef24829f95a819965214eeae28e3289a91a61.tar.xz glibc-c52ef24829f95a819965214eeae28e3289a91a61.zip | |
regex: fix buffer read overrun in search [BZ#28470]
Problem reported by Benno Schulenberg in: https://lists.gnu.org/r/bug-gnulib/2021-10/msg00035.html * posix/regexec.c (re_search_internal): Use better bounds check.
| -rw-r--r-- | posix/regexec.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/posix/regexec.c b/posix/regexec.c index 83e9aaf8ca..6aeba3c0b4 100644 --- a/posix/regexec.c +++ b/posix/regexec.c @@ -758,10 +758,9 @@ re_search_internal (const regex_t *preg, const char *string, Idx length, offset = match_first - mctx.input.raw_mbs_idx; } - /* If MATCH_FIRST is out of the buffer, leave it as '\0'. - Note that MATCH_FIRST must not be smaller than 0. */ - ch = (match_first >= length - ? 0 : re_string_byte_at (&mctx.input, offset)); + /* Use buffer byte if OFFSET is in buffer, otherwise '\0'. */ + ch = (offset < mctx.input.valid_len + ? re_string_byte_at (&mctx.input, offset) : 0); if (fastmap[ch]) break; match_first += incr; |