From 0093ac8d57a0f1a16fd09d98f6a524dddb6053e7 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Thu, 13 Mar 2014 17:05:04 -0700 Subject: ln: with -sr, don't segfault for a TARGET of '' Prior to this change, "ln -sr '' F" would segfault, attempting to read path2[1] in relpath.c's path_common_prefix function. This problem arises whenever canonicalize_filename_mode returns NULL. * src/ln.c (convert_abs_rel): Call relpath only when both canonicalize_filename_mode calls return non-NULL. * tests/ln/relative.sh: Add a test to trigger this failure. * THANKS.in: List reporter's name/address. * NEWS (Bug fixes): Mention it. Reported by Erik Bernstein in 739752@bugs.debian.org. Fixes http://bugs.gnu.org/17010. --- src/ln.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'src') diff --git a/src/ln.c b/src/ln.c index aab9cf2fa..67266997e 100644 --- a/src/ln.c +++ b/src/ln.c @@ -149,13 +149,17 @@ convert_abs_rel (const char *from, const char *target) char *realdest = canonicalize_filename_mode (targetdir, CAN_MISSING); char *realfrom = canonicalize_filename_mode (from, CAN_MISSING); - /* Write to a PATH_MAX buffer. */ - char *relative_from = xmalloc (PATH_MAX); - - if (!relpath (realfrom, realdest, relative_from, PATH_MAX)) + char *relative_from = NULL; + if (realdest && realfrom) { - free (relative_from); - relative_from = NULL; + /* Write to a PATH_MAX buffer. */ + relative_from = xmalloc (PATH_MAX); + + if (!relpath (realfrom, realdest, relative_from, PATH_MAX)) + { + free (relative_from); + relative_from = NULL; + } } free (targetdir); -- cgit v1.2.3-54-g00ecf