Correctly handle readlink overflow.

* safepath.h (SAFEPATH_TOOLONG): New enum constant.

* safepath.c (safepatch_check): Don't ignore the truncation
situation from readlink. Use the full buffer length,
and if readlink returns 256, then diagnose overflow using the
new SAFEPATH_TOOLONG error code and bail.
(safepath_strerr): Map SAFEPATH_TOOLONG.

1 files changed, 1 insertions, 0 deletions

diff --git a/safepath.h b/safepath.h
index 766a163..99786b1 100644
--- a/safepath.h
+++ b/safepath.h
@@ -45,6 +45,7 @@ enum {
   SAFEPATH_INVAL,               /* path is invalid */
   SAFEPATH_NOMEM,               /* out of memory */
   SAFEPATH_LOOP,                /* more than 8 levels of symlink */
+  SAFEPATH_TOOLONG,             /* component or symlink target too long */
 };
 
 int safepath_check(const char *name);