alloc-util: add strdupa_safe() + strndupa_safe() and use it everywhere

Let's define two helpers strdupa_safe() + strndupa_safe() which do the
same as their non-safe counterparts, except that they abort if called
with allocations larger than ALLOCA_MAX.

This should ensure that all our alloca() based allocations are subject
to this limit.

afaics glibc offers three alloca() based APIs: alloca() itself,
strndupa() + strdupa(). With this we have now replacements for all of
them, that take the limit into account.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/coredump/coredump-vacuum.c b/src/coredump/coredump-vacuum.c
index 95c3fca661..0c08ab21dc 100644
--- a/src/coredump/coredump-vacuum.c
+++ b/src/coredump/coredump-vacuum.c
@@ -61,7 +61,7 @@ static int uid_from_file_name(const char *filename, uid_t *uid) {
         if (!e)
                 return -EINVAL;
 
-        u = strndupa(p, e-p);
+        u = strndupa_safe(p, e - p);
         return parse_uid(u, uid);
 }