[PATCH 1/6] smb/server: fix null-ptr-deref in ksmbd_ipc_tree_connect_request()

[ZhangGuoDong <zhang.guodong@linux.dev>]

From: ZhangGuoDong <zhangguodong@kylinos.cn>

See the procedure below:

  ksmbd_tree_conn_connect
    ksmbd_share_config_get
      share->name = kstrdup() // fail
      if (!test_share_config_flag(share, KSMBD_SHARE_FLAG_PIPE)) // false
      // do not check `share->name`
    ksmbd_ipc_tree_connect_request
      strlen(share->name) // null-ptr-deref

Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
---
 fs/smb/server/mgmt/share_config.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/smb/server/mgmt/share_config.c b/fs/smb/server/mgmt/share_config.c
index 1cb58bec0903..53d6f71dd871 100644
--- a/fs/smb/server/mgmt/share_config.c
+++ b/fs/smb/server/mgmt/share_config.c
@@ -215,6 +215,11 @@ static struct ksmbd_share_config *share_config_request(struct ksmbd_work *work,
 	ksmbd_share_tree_conn_init(share);
 	INIT_LIST_HEAD(&share->veto_list);
 	share->name = kstrdup(name, KSMBD_DEFAULT_GFP);
+	if (!share->name) {
+		kill_share(share);
+		share = NULL;
+		goto out;
+	}
 
 	if (!test_share_config_flag(share, KSMBD_SHARE_FLAG_PIPE)) {
 		int path_len = PATH_MAX;
@@ -260,7 +265,7 @@ static struct ksmbd_share_config *share_config_request(struct ksmbd_work *work,
 				share->path = NULL;
 			}
 		}
-		if (ret || !share->name) {
+		if (ret) {
 			kill_share(share);
 			share = NULL;
 			goto out;
-- 
2.54.0