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From:   Su Hui <suhui@nfschina.com>
To:     trond.myklebust@hammerspace.com, anna@kernel.org,
        chuck.lever@oracle.com, jlayton@kernel.org, neilb@suse.de,
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Cc:     bfields@fieldses.org, linux-nfs@vger.kernel.org,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        kernel-janitors@vger.kernel.org, Su Hui <suhui@nfschina.com>
Subject: [PATCH v2] fs: lockd: avoid possible wrong NULL parameter
Date:   Fri,  4 Aug 2023 09:26:57 +0800
Message-Id: <20230804012656.4091877-1-suhui@nfschina.com>
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clang's static analysis warning: fs/lockd/mon.c: line 293, column 2:
Null pointer passed as 2nd argument to memory copy function.

Assuming 'hostname' is NULL and calling 'nsm_create_handle()', this will
pass NULL as 2nd argument to memory copy function 'memcpy()'. So return
NULL if 'hostname' is invalid.

Fixes: 77a3ef33e2de ("NSM: More clean up of nsm_get_handle()")
Signed-off-by: Su Hui <suhui@nfschina.com>
---
v2:
 - move NULL check to the callee "nsm_create_handle()"
 fs/lockd/mon.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 1d9488cf0534..87a0f207df0b 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -276,6 +276,9 @@ static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
 {
 	struct nsm_handle *new;
 
+	if (!hostname)
+		return NULL;
+
 	new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
 	if (unlikely(new == NULL))
 		return NULL;
-- 
2.30.2