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Message-Id: <20201124122421.9859-1-kda@linux-powerpc.org>
Date: Tue, 24 Nov 2020 15:24:21 +0300
From: Denis Kirjanov <kda@...ux-powerpc.org>
To: netdev@...r.kernel.org
Cc: kuba@...nel.org, davem@...emloft.net
Subject: [PATCH] net/af_unix: don't create a path for a binded socket
in the case of the socket which is bound to an adress
there is no sense to create a path in the next attempts
here is a program that shows the issue:
int main()
{
int s;
struct sockaddr_un a;
s = socket(AF_UNIX, SOCK_STREAM, 0);
if (s<0)
perror("socket() failed\n");
printf("First bind()\n");
memset(&a, 0, sizeof(a));
a.sun_family = AF_UNIX;
strncpy(a.sun_path, "/tmp/.first_bind", sizeof(a.sun_path));
if ((bind(s, (const struct sockaddr*) &a, sizeof(a))) == -1)
perror("bind() failed\n");
printf("Second bind()\n");
memset(&a, 0, sizeof(a));
a.sun_family = AF_UNIX;
strncpy(a.sun_path, "/tmp/.first_bind_failed", sizeof(a.sun_path));
if ((bind(s, (const struct sockaddr*) &a, sizeof(a))) == -1)
perror("bind() failed\n");
}
kda@...S15-SP2:~> ./test
First bind()
Second bind()
bind() failed
: Invalid argument
kda@...S15-SP2:~> ls -la /tmp/.first_bind
.first_bind .first_bind_failed
Signed-off-by: Denis Kirjanov <kda@...ux-powerpc.org>
---
net/unix/af_unix.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 41c3303c3357..fd76a8fe3907 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1021,7 +1021,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
err = -EINVAL;
if (addr_len < offsetofend(struct sockaddr_un, sun_family) ||
- sunaddr->sun_family != AF_UNIX)
+ sunaddr->sun_family != AF_UNIX || u->addr)
goto out;
if (addr_len == sizeof(short)) {
@@ -1049,10 +1049,6 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
if (err)
goto out_put;
- err = -EINVAL;
- if (u->addr)
- goto out_up;
-
err = -ENOMEM;
addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
if (!addr)
--
2.16.4
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