Commit 00b67657 authored by John Johansen's avatar John Johansen
Browse files

apparmor: fix NULL sock in aa_sock_file_perm 



Deal with the potential that sock and sock-sk can be NULL during
socket setup or teardown. This could lead to an oops. The fix for NULL
pointer dereference in __unix_needs_revalidation shows this is at
least possible for af_unix sockets. While the fix for af_unix sockets
applies for newer mediation this is still the fall back path for older
af_unix mediation and other sockets, so ensure it is covered.

Fixes: 56974a6f ("apparmor: add base infastructure for socket mediation")
Reviewed-by: default avatarGeorgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: default avatarJohn Johansen <john.johansen@canonical.com>
parent e2938ad0

security/apparmor/net.c

+4 −2
Original line number Diff line number Diff line
@@ -326,8 +326,10 @@ int aa_sock_file_perm(const struct cred *subj_cred, struct aa_label *label, 
	struct socket *sock = (struct socket *) file->private_data;



	AA_BUG(!label);

	AA_BUG(!sock);

	AA_BUG(!sock->sk);



	/* sock && sock->sk can be NULL for sockets being set up or torn down */

	if (!sock || !sock->sk)

		return 0;



	if (sock->sk->sk_family == PF_UNIX)

		return aa_unix_file_perm(subj_cred, label, op, request, file);