This is a note to let you know that I've just added the patch titled gtp: fix a potential NULL pointer dereference to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: gtp-fix-a-potential-null-pointer-dereference.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit a556b3e3abb0461855f88428bb0e7de0f25f7593 Author: Cong Wang <cong.wang@xxxxxxxxxxxxx> Date: Sun Aug 25 12:16:38 2024 -0700 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: 1e3a3abd8b28 ("gtp: make GTP sockets in gtp_newlink optional") Cc: Andreas Schultz <aschultz@xxxxxxxx> Cc: Harald Welte <laforge@xxxxxxxxxxxx> Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx> Reviewed-by: Simon Horman <horms@xxxxxxxxxx> Reviewed-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Link: https://patch.msgid.link/20240825191638.146748-1-xiyou.wangcong@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index cc80bd98e172d..733cafb0888f6 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -812,7 +812,7 @@ static struct sock *gtp_encap_enable_socket(int fd, int type, sock = sockfd_lookup(fd, &err); if (!sock) { pr_debug("gtp socket fd=%d not found\n", fd); - return NULL; + return ERR_PTR(err); } sk = sock->sk;