linux-kernel - [PATCH] net: sunrpc: Fix 'snprintf' return value check in 'do_xprt

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20201015135341.GA16343@laptop>
Date:   Thu, 15 Oct 2020 16:59:08 +0300
From:   Fedor Tokarev <ftokarev@...il.com>
To:     bfields@...ldses.org, chuck.lever@...cle.com,
        anna.schumaker@...app.com, trond.myklebust@...merspace.com,
        davem@...emloft.net, kuba@...nel.org
Cc:     linux-nfs@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org,
        ftokarev@...il.com
Subject: [PATCH] net: sunrpc: Fix 'snprintf' return value check in
 'do_xprt_debugfs'

'snprintf' returns the number of characters which would have been written
if enough space had been available, excluding the terminating null byte.
Thus, the return value of 'sizeof(buf)' means that the last character
has been dropped.

Signed-off-by: Fedor Tokarev <ftokarev@...il.com>
---
 net/sunrpc/debugfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c
index fd9bca2..56029e3 100644
--- a/net/sunrpc/debugfs.c
+++ b/net/sunrpc/debugfs.c
@@ -128,13 +128,13 @@ static int do_xprt_debugfs(struct rpc_clnt *clnt, struct rpc_xprt *xprt, void *n
 		return 0;
 	len = snprintf(name, sizeof(name), "../../rpc_xprt/%s",
 		       xprt->debugfs->d_name.name);
-	if (len > sizeof(name))
+	if (len >= sizeof(name))
 		return -1;
 	if (*nump == 0)
 		strcpy(link, "xprt");
 	else {
 		len = snprintf(link, sizeof(link), "xprt%d", *nump);
-		if (len > sizeof(link))
+		if (len >= sizeof(link))
 			return -1;
 	}
 	debugfs_create_symlink(link, clnt->cl_debugfs, name);
-- 
2.7.4