diff options
| author |   otto <otto@openbsd.org> | 2004-04-02 18:34:33 +0000 |
|---|---|---|
| committer | otto <otto@openbsd.org> | 2004-04-02 18:34:33 +0000 |
| commit | 2617cd22e38992f4cc44590298b0c107826d1059 (patch) | |
| tree | fe34ee82ecd95750257b20c2265f9a2528f07d28 /lib/libc/regex/engine.c | |
| parent | spelink (diff) | |
| download | wireguard-openbsd-2617cd22e38992f4cc44590298b0c107826d1059.tar.xz wireguard-openbsd-2617cd22e38992f4cc44590298b0c107826d1059.zip | |
Avoid unbounded recursion in some expressions involving back references.
For example:
echo "foo foo bar bar bar baz" | sed 's/\([^ ]*\)\( *\1\)*/\1/g'
Test case found by dhartmei@
ok millert@ dhartmei@ tedu@
Diffstat (limited to 'lib/libc/regex/engine.c')
| -rw-r--r-- | lib/libc/regex/engine.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/libc/regex/engine.c b/lib/libc/regex/engine.c index cafa1bb65b3..9f24b201a2a 100644 --- a/lib/libc/regex/engine.c +++ b/lib/libc/regex/engine.c @@ -1,4 +1,4 @@ -/* $OpenBSD: engine.c,v 1.8 2004/03/30 20:36:07 millert Exp $ */ +/* $OpenBSD: engine.c,v 1.9 2004/04/02 18:34:33 otto Exp $ */ /*- * Copyright (c) 1992, 1993, 1994 Henry Spencer. @@ -36,7 +36,7 @@ */ #if defined(SNAMES) && defined(LIBC_SCCS) && !defined(lint) -static char enginercsid[] = "$OpenBSD: engine.c,v 1.8 2004/03/30 20:36:07 millert Exp $"; +static char enginercsid[] = "$OpenBSD: engine.c,v 1.9 2004/04/02 18:34:33 otto Exp $"; #endif /* SNAMES and LIBC_SCCS and not lint */ /* @@ -607,6 +607,8 @@ sopno lev; /* PLUS nesting level */ return(NULL); assert(m->pmatch[i].rm_so != -1); len = m->pmatch[i].rm_eo - m->pmatch[i].rm_so; + if (len == 0) + return(NULL); assert(stop - m->beginp >= len); if (sp > stop - len) return(NULL); /* not enough left to match */ |