[PATCH v1] fs: proc: Add error checking for d_hash_and_lookup()

From: Wang Ming <machel@vivo.com>
To: Christian Brauner <brauner@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Dave Chinner <dchinner@redhat.com>,
	Xiaokai Ran <ran.xiaokai@zte.com.cn>,
	Al Viro <viro@zeniv.linux.org.uk>, xu xin <xu.xin16@zte.com.cn>,
	Zhihao Cheng <chengzhihao1@huawei.com>,
	"Liam R. Howlett" <Liam.Howlett@Oracle.com>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: opensource.kernel@vivo.com, Wang Ming <machel@vivo.com>
Subject: [PATCH v1] fs: proc: Add error checking for d_hash_and_lookup()
Date: Thu, 13 Jul 2023 19:32:48 +0800	[thread overview]
Message-ID: <20230713113303.6512-1-machel@vivo.com> (raw)

In case of failure, d_hash_and_lookup() returns NULL or an error
pointer. The proc_fill_cache() needs to add the handling of the
error pointer returned by d_hash_and_lookup().

Signed-off-by: Wang Ming <machel@vivo.com>
---
 fs/proc/base.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index bbc998fd2a2f..4c0e8329b318 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2071,6 +2071,8 @@ bool proc_fill_cache(struct file *file, struct dir_context *ctx,
 	ino_t ino = 1;
 
 	child = d_hash_and_lookup(dir, &qname);
+	if (IS_ERR(child))
+		goto end_instantiate;
 	if (!child) {
 		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
 		child = d_alloc_parallel(dir, &qname, &wq);
-- 
2.25.1

