selinux: do not leave dangling pointer behind

In case mls_context_cpy() fails due to OOM set the free'd pointer in
context_cpy() to NULL to avoid it potentially being dereferenced or
free'd again in future.  Freeing a NULL pointer is well-defined and a
hard NULL dereference crash is at least not exploitable and should give
a workable stack trace.

Fixes: 12b29f3455 ("selinux: support deferred mapping of contexts")
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Christian Göttsche 2023-04-20 17:04:58 +02:00 • committed by Paul Moore
commit 53f3517ae0