From: Jens Axboe axboe@kernel.dk
[ Upstream commit d69e07793f891524c6bbf1e75b9ae69db4450953 ]
Only io_uring uses (and added) these, and we want to disallow the use of sendmsg/recvmsg for anything but regular data transfers. Use the newly added prep helper to split the msghdr copy out from the core function, to check for msg_control and msg_controllen settings. If either is set, we return -EINVAL.
Acked-by: David S. Miller davem@davemloft.net Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- net/socket.c | 43 +++++++++++++++++++++++++++++++++++++------ 1 file changed, 37 insertions(+), 6 deletions(-)
diff --git a/net/socket.c b/net/socket.c index fbe08d7df7732..d7a106028f0e0 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2357,12 +2357,27 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, /* * BSD sendmsg interface */ -long __sys_sendmsg_sock(struct socket *sock, struct user_msghdr __user *msg, +long __sys_sendmsg_sock(struct socket *sock, struct user_msghdr __user *umsg, unsigned int flags) { - struct msghdr msg_sys; + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + struct sockaddr_storage address; + struct msghdr msg = { .msg_name = &address }; + ssize_t err; + + err = sendmsg_copy_msghdr(&msg, umsg, flags, &iov); + if (err) + return err; + /* disallow ancillary data requests from this path */ + if (msg.msg_control || msg.msg_controllen) { + err = -EINVAL; + goto out; + }
- return ___sys_sendmsg(sock, msg, &msg_sys, flags, NULL, 0); + err = ____sys_sendmsg(sock, &msg, flags, NULL, 0); +out: + kfree(iov); + return err; }
long __sys_sendmsg(int fd, struct user_msghdr __user *msg, unsigned int flags, @@ -2561,12 +2576,28 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg, * BSD recvmsg interface */
-long __sys_recvmsg_sock(struct socket *sock, struct user_msghdr __user *msg, +long __sys_recvmsg_sock(struct socket *sock, struct user_msghdr __user *umsg, unsigned int flags) { - struct msghdr msg_sys; + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + struct sockaddr_storage address; + struct msghdr msg = { .msg_name = &address }; + struct sockaddr __user *uaddr; + ssize_t err;
- return ___sys_recvmsg(sock, msg, &msg_sys, flags, 0); + err = recvmsg_copy_msghdr(&msg, umsg, flags, &uaddr, &iov); + if (err) + return err; + /* disallow ancillary data requests from this path */ + if (msg.msg_control || msg.msg_controllen) { + err = -EINVAL; + goto out; + } + + err = ____sys_recvmsg(sock, &msg, umsg, uaddr, flags, 0); +out: + kfree(iov); + return err; }
long __sys_recvmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,