From: Ani Sinha <ani@xxxxxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 6a2a2b3ae0759843b22c929881cc184b00cc63ff upstream. Linux manpage for recvmsg and sendmsg calls does not explicitly mention setting msg_namelen to 0 when msg_name passed set as NULL. When developers don't set msg_namelen member in msghdr, it might contain garbage value which will fail the validation check and sendmsg and recvmsg calls from kernel will return EINVAL. This will break old binaries and any code for which there is no access to source code. To fix this, we set msg_namelen to 0 when msg_name is passed as NULL from userland. Signed-off-by: Ani Sinha <ani@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- net/socket.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/socket.c b/net/socket.c index 432b0bddd9e1..00634623573f 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1970,6 +1970,9 @@ static int copy_msghdr_from_user(struct msghdr *kmsg, if (copy_from_user(kmsg, umsg, sizeof(struct msghdr))) return -EFAULT; + if (kmsg->msg_name == NULL) + kmsg->msg_namelen = 0; + if (kmsg->msg_namelen < 0) return -EINVAL; -- 2.6.3 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html