| Subject: | Segfault originating in get_sha_info() |
The get_sha_info() function in SHA1.xs does not check that its argument is an actual object. This means that segfaults can be generated by commands such as:
$ perl -Mblib -e "use Digest::SHA1; print Digest::SHA1->add(q(a))->hexdigest"
Segmentation fault
The following patch solves the problem:
diff -Naur Digest-SHA1-2.13/SHA1.xs Digest-SHA1-2.13.patched/SHA1.xs
--- Digest-SHA1-2.13/SHA1.xs 2010-07-02 23:51:12.000000000 -0700
+++ Digest-SHA1-2.13.patched/SHA1.xs 2014-03-25 12:43:53.233272555 -0700
@@ -372,7 +372,7 @@
static SHA_INFO* get_sha_info(pTHX_ SV* sv)
{
- if (sv_derived_from(sv, "Digest::SHA1"))
+ if (sv_isobject(sv) && sv_derived_from(sv, "Digest::SHA1"))
return INT2PTR(SHA_INFO*, SvIV(SvRV(sv)));
croak("Not a reference to a Digest::SHA1 object");
return (SHA_INFO*)0; /* some compilers insist on a return value */
as can be seen from the revised output:
$ perl -Mblib -e "use Digest::SHA1; print Digest::SHA1->add(q(a))->hexdigest"
Not a reference to a Digest::SHA1 object at -e line 1.
Mark