netdev - [PATCH 2/5] net/handshake: Fix handshake

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: 
 <168321389545.16695.14828237648251844351.stgit@oracle-102.nfsv4bat.org>
Date: Thu, 04 May 2023 11:25:05 -0400
From: Chuck Lever <cel@...nel.org>
To: kernel-tls-handshake@...ts.linux.dev
Cc: netdev@...r.kernel.org, dan.carpenter@...aro.org
Subject: [PATCH 2/5] net/handshake: Fix handshake_dup() ref counting

From: Chuck Lever <chuck.lever@...cle.com>

If get_unused_fd_flags() fails, we ended up calling fput(sock->file)
twice.

Reported-by: Dan Carpenter <dan.carpenter@...aro.org>
Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests")
Signed-off-by: Chuck Lever <chuck.lever@...cle.com>
---
 net/handshake/netlink.c |   10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/net/handshake/netlink.c b/net/handshake/netlink.c
index 7ec8a76c3c8a..3508bc3e661d 100644
--- a/net/handshake/netlink.c
+++ b/net/handshake/netlink.c
@@ -96,17 +96,13 @@ EXPORT_SYMBOL(handshake_genl_put);
  */
 static int handshake_dup(struct socket *sock)
 {
-	struct file *file;
 	int newfd;
 
-	file = get_file(sock->file);
 	newfd = get_unused_fd_flags(O_CLOEXEC);
-	if (newfd < 0) {
-		fput(file);
+	if (newfd < 0)
 		return newfd;
-	}
 
-	fd_install(newfd, file);
+	fd_install(newfd, sock->file);
 	return newfd;
 }
 
@@ -143,11 +139,11 @@ int handshake_nl_accept_doit(struct sk_buff *skb, struct genl_info *info)
 		goto out_complete;
 
 	trace_handshake_cmd_accept(net, req, req->hr_sk, fd);
+	get_file(sock->file);	/* released by DONE */
 	return 0;
 
 out_complete:
 	handshake_complete(req, -EIO, NULL);
-	fput(sock->file);
 out_status:
 	trace_handshake_cmd_accept_err(net, req, NULL, err);
 	return err;