Commit bdd99e5f authored Aug 25, 2024 by Cong Wang Committed by Greg Kroah-Hartman Sep 04, 2024

gtp: fix a potential NULL pointer dereference



[ Upstream commit defd8b3c37b0f9cb3e0f60f47d3d78d459d57fda ]

When sockfd_lookup() fails, gtp_encap_enable_socket() returns a
NULL pointer, but its callers only check for error pointers thus miss
the NULL pointer case.

Fix it by returning an error pointer with the error code carried from
sockfd_lookup().

(I found this bug during code inspection.)

Fixes: 1e3a3abd ("gtp: make GTP sockets in gtp_newlink optional")
Cc: Andreas Schultz <aschultz@tpip.net>
Cc: Harald Welte <laforge@gnumonks.org>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://patch.msgid.link/20240825191638.146748-1-xiyou.wangcong@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent ec7b4f7f

drivers/net/gtp.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -807,7 +807,7 @@ static struct sock *gtp_encap_enable_socket(int fd, int type,
	sock = sockfd_lookup(fd, &err);		sock = sockfd_lookup(fd, &err);
	if (!sock) {		if (!sock) {
	pr_debug("gtp socket fd=%d not found\n", fd);		pr_debug("gtp socket fd=%d not found\n", fd);
	return NULL;		return ERR_PTR(err);
	}		}

	sk = sock->sk;		sk = sock->sk;