[PATCH] Tools: hv: verify origin of netlink connector message

[PATCH] Tools: hv: verify origin of netlink connector message

[Olaf Hering]

The SuSE security team suggested to use recvfrom instead of recv to be
certain that the connector message is originated from kernel.

Signed-off-by: Olaf Hering <olaf@aepfle.de>

---
 tools/hv/hv_kvp_daemon.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

Index: linux-3.4/tools/hv/hv_kvp_daemon.c
===================================================================
--- linux-3.4.orig/tools/hv/hv_kvp_daemon.c
+++ linux-3.4/tools/hv/hv_kvp_daemon.c
@@ -701,14 +701,18 @@ int main(void)
 	pfd.fd = fd;
 
 	while (1) {
+		struct sockaddr *addr_p = (struct sockaddr *) &addr;
+		socklen_t addr_l = sizeof(addr);
 		pfd.events = POLLIN;
 		pfd.revents = 0;
 		poll(&pfd, 1, -1);
 
-		len = recv(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0);
+		len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0,
+				addr_p, &addr_l);
 
-		if (len < 0) {
-			syslog(LOG_ERR, "recv failed; error:%d", len);
+		if (len < 0 || addr.nl_pid) {
+			syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
+					addr.nl_pid, errno, strerror(errno));
 			close(fd);
 			return -1;
 		}

RE: [PATCH] Tools: hv: verify origin of netlink connector message

[KY Srinivasan]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1667 bytes --]



> -----Original Message-----
> From: Olaf Hering [mailto:olaf@aepfle.de]
> Sent: Thursday, May 31, 2012 10:40 AM
> To: KY Srinivasan; Greg Kroah-Hartman
> Cc: linux-kernel@vger.kernel.org
> Subject: [PATCH] Tools: hv: verify origin of netlink connector message
> 
> The SuSE security team suggested to use recvfrom instead of recv to be
> certain that the connector message is originated from kernel.

Thanks Olaf.

> 
> Signed-off-by: Olaf Hering <olaf@aepfle.de>

Signed-off-by:  K. Y. Srinivasan <kys@microsoft.com>

> 
> ---
>  tools/hv/hv_kvp_daemon.c |   10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> Index: linux-3.4/tools/hv/hv_kvp_daemon.c
> ==============================================================
> =====
> --- linux-3.4.orig/tools/hv/hv_kvp_daemon.c
> +++ linux-3.4/tools/hv/hv_kvp_daemon.c
> @@ -701,14 +701,18 @@ int main(void)
>  	pfd.fd = fd;
> 
>  	while (1) {
> +		struct sockaddr *addr_p = (struct sockaddr *) &addr;
> +		socklen_t addr_l = sizeof(addr);
>  		pfd.events = POLLIN;
>  		pfd.revents = 0;
>  		poll(&pfd, 1, -1);
> 
> -		len = recv(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0);
> +		len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0,
> +				addr_p, &addr_l);
> 
> -		if (len < 0) {
> -			syslog(LOG_ERR, "recv failed; error:%d", len);
> +		if (len < 0 || addr.nl_pid) {
> +			syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
> +					addr.nl_pid, errno, strerror(errno));
>  			close(fd);
>  			return -1;
>  		}
> 
> 

ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥