[PATCH 1/1] unshare: fix nsproxy leak in ksys_unshare() on set_cred_ucounts() failure

[Michal Grzedzicki <mge@meta.com>]

When set_cred_ucounts() fails in ksys_unshare() new_nsproxy is leaked.

Let's call put_nsproxy() if that happens.

Fixes: 905ae01c4ae2 ("Add a reference to ucounts for each cred")
Signed-off-by: Michal Grzedzicki <mge@meta.com>
---
 kernel/fork.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index e832da9d15a4..f6a5ed2067b7 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -3175,11 +3175,10 @@ int ksys_unshare(unsigned long unshare_flags)
 					 new_cred, new_fs);
 	if (err)
 		goto bad_unshare_cleanup_cred;
-
 	if (new_cred) {
 		err = set_cred_ucounts(new_cred);
 		if (err)
-			goto bad_unshare_cleanup_cred;
+			goto bad_unshare_cleanup_nsproxy;
 	}
 
 	if (new_fs || new_fd || do_sysvsem || new_cred || new_nsproxy) {
@@ -3195,8 +3194,10 @@ int ksys_unshare(unsigned long unshare_flags)
 			shm_init_task(current);
 		}
 
-		if (new_nsproxy)
+		if (new_nsproxy) {
 			switch_task_namespaces(current, new_nsproxy);
+			new_nsproxy = NULL;
+		}
 
 		task_lock(current);
 
@@ -3225,13 +3226,15 @@ int ksys_unshare(unsigned long unshare_flags)
 
 	perf_event_namespaces(current);
 
+bad_unshare_cleanup_nsproxy:
+	if (new_nsproxy)
+		put_nsproxy(new_nsproxy);
 bad_unshare_cleanup_cred:
 	if (new_cred)
 		put_cred(new_cred);
 bad_unshare_cleanup_fd:
 	if (new_fd)
 		put_files_struct(new_fd);
-
 bad_unshare_cleanup_fs:
 	if (new_fs)
 		free_fs_struct(new_fs);
-- 
2.47.3