[PATCH 6.11 07/12] netfilter: nft_socket: Fix a NULL vs IS_ERR() bug in nft_socket_cgroup_subtree_level()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@linaro.org>

commit 7052622fccb1efb850c6b55de477f65d03525a30 upstream.

The cgroup_get_from_path() function never returns NULL, it returns error
pointers.  Update the error handling to match.

Fixes: 7f3287db6543 ("netfilter: nft_socket: make cgroupsv2 matching work with namespaces")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://patch.msgid.link/bbc0c4e0-05cc-4f44-8797-2f4b3920a820@stanley.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/netfilter/nft_socket.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/netfilter/nft_socket.c
+++ b/net/netfilter/nft_socket.c
@@ -61,8 +61,8 @@ static noinline int nft_socket_cgroup_su
 	struct cgroup *cgrp = cgroup_get_from_path("/");
 	int level;
 
-	if (!cgrp)
-		return -ENOENT;
+	if (IS_ERR(cgrp))
+		return PTR_ERR(cgrp);
 
 	level = cgrp->level;