diff options
| author | Jens Axboe <axboe@kernel.dk> | 2019-11-25 17:04:13 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-11-26 15:02:53 -0700 |
| commit | d69e07793f891524c6bbf1e75b9ae69db4450953 (patch) | |
| tree | 054fc5da5cbcbc2922575d0f13b83d5023c96755 | |
| parent | 4257c8ca13b084550574b8c9a667d9c90ff746eb (diff) | |
| download | linux-d69e07793f891524c6bbf1e75b9ae69db4450953.tar.bz2 | |
net: disallow ancillary data for __sys_{send,recv}msg_file()
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>
| -rw-r--r-- | net/socket.c | 43 |
1 files changed, 37 insertions, 6 deletions
diff --git a/net/socket.c b/net/socket.c index 98568ae58bad..c78c3d37c884 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2389,12 +2389,27 @@ 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, @@ -2593,12 +2608,28 @@ 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, |