From eb7eb184acef1e803629b0cdcf1afc90bff62e1a Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 27 Nov 2013 15:40:21 +0300 Subject: [PATCH] net: clamp ->msg_namelen instead of returning an error [ Upstream commit db31c55a6fb245fdbb752a2ca4aefec89afabb06 ] If kmsg->msg_namelen > sizeof(struct sockaddr_storage) then in the original code that would lead to memory corruption in the kernel if you had audit configured. If you didn't have audit configured it was harmless. There are some programs such as beta versions of Ruby which use too large of a buffer and returning an error code breaks them. We should clamp the ->msg_namelen value instead. Fixes: 1661bf364ae9 ("net: heap overflow in __audit_sockaddr()") Reported-by: Eric Wong Signed-off-by: Dan Carpenter Tested-by: Eric Wong Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/compat.c | 2 +- net/socket.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/net/compat.c b/net/compat.c index 318a876..17f997e 100644 --- a/net/compat.c +++ b/net/compat.c @@ -72,7 +72,7 @@ int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg) __get_user(kmsg->msg_flags, &umsg->msg_flags)) return -EFAULT; if (kmsg->msg_namelen > sizeof(struct sockaddr_storage)) - return -EINVAL; + kmsg->msg_namelen = sizeof(struct sockaddr_storage); kmsg->msg_name = compat_ptr(tmp1); kmsg->msg_iov = compat_ptr(tmp2); kmsg->msg_control = compat_ptr(tmp3); diff --git a/net/socket.c b/net/socket.c index 573e212..4006452 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1908,7 +1908,7 @@ static int copy_msghdr_from_user(struct msghdr *kmsg, if (copy_from_user(kmsg, umsg, sizeof(struct msghdr))) return -EFAULT; if (kmsg->msg_namelen > sizeof(struct sockaddr_storage)) - return -EINVAL; + kmsg->msg_namelen = sizeof(struct sockaddr_storage); return 0; } -- 2.7.4