Commit 7515e37b authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso Committed by Jakub Kicinski
Browse files

gtp: allow -1 to be specified as file description from userspace 



Existing user space applications maintained by the Osmocom project are
breaking since a recent fix that addresses incorrect error checking.

Restore operation for user space programs that specify -1 as file
descriptor to skip GTPv0 or GTPv1 only sockets.

Fixes: defd8b3c ("gtp: fix a potential NULL pointer dereference")
Reported-by: default avatarPau Espin Pedrol <pespin@sysmocom.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Tested-by: default avatarOliver Smith <osmith@sysmocom.de>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241022144825.66740-1-pablo@netfilter.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 01e21597

drivers/net/gtp.c

+13 −9
Original line number Diff line number Diff line
@@ -1702,22 +1702,26 @@ static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]) 
		return -EINVAL;



	if (data[IFLA_GTP_FD0]) {

		u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);

		int fd0 = nla_get_u32(data[IFLA_GTP_FD0]);



		if (fd0 >= 0) {

			sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);

			if (IS_ERR(sk0))

				return PTR_ERR(sk0);

		}

	}



	if (data[IFLA_GTP_FD1]) {

		u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);

		int fd1 = nla_get_u32(data[IFLA_GTP_FD1]);



		if (fd1 >= 0) {

			sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);

			if (IS_ERR(sk1u)) {

				gtp_encap_disable_sock(sk0);

				return PTR_ERR(sk1u);

			}

		}

	}



	gtp->sk0 = sk0;

	gtp->sk1u = sk1u;