From: Jens Axboe axboe@kernel.dk
mainline inclusion from mainline-5.5-rc1 commit 4257c8ca13b084550574b8c9a667d9c90ff746eb category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA ---------------------------
This is in preparation for enabling the io_uring helpers for sendmsg and recvmsg to first copy the header for validation before continuing with the operation.
There should be no functional changes in this patch.
Acked-by: David S. Miller davem@davemloft.net Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- net/socket.c | 141 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 95 insertions(+), 46 deletions(-)
diff --git a/net/socket.c b/net/socket.c index 8faf6ea75c61..b4fd9c96e2ed 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2068,15 +2068,10 @@ static int copy_msghdr_from_user(struct msghdr *kmsg, return err < 0 ? err : 0; }
-static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, - struct msghdr *msg_sys, unsigned int flags, - struct used_address *used_address, - unsigned int allowed_msghdr_flags) +static int ____sys_sendmsg(struct socket *sock, struct msghdr *msg_sys, + unsigned int flags, struct used_address *used_address, + unsigned int allowed_msghdr_flags) { - struct compat_msghdr __user *msg_compat = - (struct compat_msghdr __user *)msg; - struct sockaddr_storage address; - struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; unsigned char ctl[sizeof(struct cmsghdr) + 20] __aligned(sizeof(__kernel_size_t)); /* 20 is size of ipv6_pktinfo */ @@ -2084,19 +2079,10 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, int ctl_len; ssize_t err;
- msg_sys->msg_name = &address; - - if (MSG_CMSG_COMPAT & flags) - err = get_compat_msghdr(msg_sys, msg_compat, NULL, &iov); - else - err = copy_msghdr_from_user(msg_sys, msg, NULL, &iov); - if (err < 0) - return err; - err = -ENOBUFS;
if (msg_sys->msg_controllen > INT_MAX) - goto out_freeiov; + goto out; flags |= (msg_sys->msg_flags & allowed_msghdr_flags); ctl_len = msg_sys->msg_controllen; if ((MSG_CMSG_COMPAT & flags) && ctl_len) { @@ -2104,7 +2090,7 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, cmsghdr_from_user_compat_to_kern(msg_sys, sock->sk, ctl, sizeof(ctl)); if (err) - goto out_freeiov; + goto out; ctl_buf = msg_sys->msg_control; ctl_len = msg_sys->msg_controllen; } else if (ctl_len) { @@ -2113,7 +2099,7 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, if (ctl_len > sizeof(ctl)) { ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL); if (ctl_buf == NULL) - goto out_freeiov; + goto out; } err = -EFAULT; /* @@ -2159,7 +2145,47 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, out_freectl: if (ctl_buf != ctl) sock_kfree_s(sock->sk, ctl_buf, ctl_len); -out_freeiov: +out: + return err; +} + +static int sendmsg_copy_msghdr(struct msghdr *msg, + struct user_msghdr __user *umsg, unsigned flags, + struct iovec **iov) +{ + int err; + + if (flags & MSG_CMSG_COMPAT) { + struct compat_msghdr __user *msg_compat; + + msg_compat = (struct compat_msghdr __user *) umsg; + err = get_compat_msghdr(msg, msg_compat, NULL, iov); + } else { + err = copy_msghdr_from_user(msg, umsg, NULL, iov); + } + if (err < 0) + return err; + + return 0; +} + +static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, + struct msghdr *msg_sys, unsigned int flags, + struct used_address *used_address, + unsigned int allowed_msghdr_flags) +{ + struct sockaddr_storage address; + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + ssize_t err; + + msg_sys->msg_name = &address; + + err = sendmsg_copy_msghdr(msg_sys, msg, flags, &iov); + if (err < 0) + return err; + + err = ____sys_sendmsg(sock, msg_sys, flags, used_address, + allowed_msghdr_flags); kfree(iov); return err; } @@ -2278,33 +2304,41 @@ SYSCALL_DEFINE4(sendmmsg, int, fd, struct mmsghdr __user *, mmsg, return __sys_sendmmsg(fd, mmsg, vlen, flags, true); }
-static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg, - struct msghdr *msg_sys, unsigned int flags, int nosec) +static int recvmsg_copy_msghdr(struct msghdr *msg, + struct user_msghdr __user *umsg, unsigned flags, + struct sockaddr __user **uaddr, + struct iovec **iov) { - struct compat_msghdr __user *msg_compat = - (struct compat_msghdr __user *)msg; - struct iovec iovstack[UIO_FASTIOV]; - struct iovec *iov = iovstack; - unsigned long cmsg_ptr; - int len; ssize_t err;
- /* kernel mode address */ - struct sockaddr_storage addr; - - /* user mode address pointers */ - struct sockaddr __user *uaddr; - int __user *uaddr_len = COMPAT_NAMELEN(msg); - - msg_sys->msg_name = &addr; + if (MSG_CMSG_COMPAT & flags) { + struct compat_msghdr __user *msg_compat;
- if (MSG_CMSG_COMPAT & flags) - err = get_compat_msghdr(msg_sys, msg_compat, &uaddr, &iov); - else - err = copy_msghdr_from_user(msg_sys, msg, &uaddr, &iov); + msg_compat = (struct compat_msghdr __user *) umsg; + err = get_compat_msghdr(msg, msg_compat, uaddr, iov); + } else { + err = copy_msghdr_from_user(msg, umsg, uaddr, iov); + } if (err < 0) return err;
+ return 0; +} + +static int ____sys_recvmsg(struct socket *sock, struct msghdr *msg_sys, + struct user_msghdr __user *msg, + struct sockaddr __user *uaddr, + unsigned int flags, int nosec) +{ + struct compat_msghdr __user *msg_compat = + (struct compat_msghdr __user *) msg; + int __user *uaddr_len = COMPAT_NAMELEN(msg); + struct sockaddr_storage addr; + unsigned long cmsg_ptr; + int len; + ssize_t err; + + msg_sys->msg_name = &addr; cmsg_ptr = (unsigned long)msg_sys->msg_control; msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
@@ -2315,7 +2349,7 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg, flags |= MSG_DONTWAIT; err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys, flags); if (err < 0) - goto out_freeiov; + goto out; len = err;
if (uaddr != NULL) { @@ -2323,12 +2357,12 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg, msg_sys->msg_namelen, uaddr, uaddr_len); if (err < 0) - goto out_freeiov; + goto out; } err = __put_user((msg_sys->msg_flags & ~MSG_CMSG_COMPAT), COMPAT_FLAGS(msg)); if (err) - goto out_freeiov; + goto out; if (MSG_CMSG_COMPAT & flags) err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr, &msg_compat->msg_controllen); @@ -2336,10 +2370,25 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg, err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr, &msg->msg_controllen); if (err) - goto out_freeiov; + goto out; err = len; +out: + return err; +} + +static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg, + struct msghdr *msg_sys, unsigned int flags, int nosec) +{ + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + /* user mode address pointers */ + struct sockaddr __user *uaddr; + ssize_t err; + + err = recvmsg_copy_msghdr(msg_sys, msg, flags, &uaddr, &iov); + if (err < 0) + return err;
-out_freeiov: + err = ____sys_recvmsg(sock, msg_sys, msg, uaddr, flags, nosec); kfree(iov); return err; }