From 72c531f8ef3052c682d39dc21dcb5576afda208c Mon Sep 17 00:00:00 2001 From: Dylan Yudaken Date: Thu, 14 Jul 2022 04:02:57 -0700 Subject: net: copy from user before calling __get_compat_msghdr this is in preparation for multishot receive from io_uring, where it needs to have access to the original struct user_msghdr. functionally this should be a no-op. Acked-by: Paolo Abeni Signed-off-by: Dylan Yudaken Link: https://lore.kernel.org/r/20220714110258.1336200-3-dylany@fb.com Signed-off-by: Jens Axboe --- include/net/compat.h | 5 ++--- io_uring/net.c | 17 +++++++++-------- net/compat.c | 39 +++++++++++++++++---------------------- 3 files changed, 28 insertions(+), 33 deletions(-) diff --git a/include/net/compat.h b/include/net/compat.h index 595fee069b82..84c163f40f38 100644 --- a/include/net/compat.h +++ b/include/net/compat.h @@ -46,9 +46,8 @@ struct compat_rtentry { unsigned short rt_irtt; /* Initial RTT */ }; -int __get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg, - struct sockaddr __user **save_addr, compat_uptr_t *ptr, - compat_size_t *len); +int __get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr *msg, + struct sockaddr __user **save_addr); int get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *, struct sockaddr __user **, struct iovec **); int put_cmsg_compat(struct msghdr*, int, int, int, void *); diff --git a/io_uring/net.c b/io_uring/net.c index da7667ed3610..5bc3440a8290 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -369,24 +369,25 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg) { struct io_sr_msg *sr = io_kiocb_to_cmd(req); + struct compat_msghdr msg; struct compat_iovec __user *uiov; - compat_uptr_t ptr; - compat_size_t len; int ret; - ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr, - &ptr, &len); + if (copy_from_user(&msg, sr->umsg_compat, sizeof(msg))) + return -EFAULT; + + ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr); if (ret) return ret; - uiov = compat_ptr(ptr); + uiov = compat_ptr(msg.msg_iov); if (req->flags & REQ_F_BUFFER_SELECT) { compat_ssize_t clen; - if (len == 0) { + if (msg.msg_iovlen == 0) { sr->len = 0; iomsg->free_iov = NULL; - } else if (len > 1) { + } else if (msg.msg_iovlen > 1) { return -EINVAL; } else { if (!access_ok(uiov, sizeof(*uiov))) @@ -400,7 +401,7 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, } } else { iomsg->free_iov = iomsg->fast_iov; - ret = __import_iovec(READ, (struct iovec __user *)uiov, len, + ret = __import_iovec(READ, (struct iovec __user *)uiov, msg.msg_iovlen, UIO_FASTIOV, &iomsg->free_iov, &iomsg->msg.msg_iter, true); if (ret < 0) diff --git a/net/compat.c b/net/compat.c index 210fc3b4d0d8..513aa9a3fc64 100644 --- a/net/compat.c +++ b/net/compat.c @@ -34,20 +34,15 @@ #include int __get_compat_msghdr(struct msghdr *kmsg, - struct compat_msghdr __user *umsg, - struct sockaddr __user **save_addr, - compat_uptr_t *ptr, compat_size_t *len) + struct compat_msghdr *msg, + struct sockaddr __user **save_addr) { - struct compat_msghdr msg; ssize_t err; - if (copy_from_user(&msg, umsg, sizeof(*umsg))) - return -EFAULT; - - kmsg->msg_flags = msg.msg_flags; - kmsg->msg_namelen = msg.msg_namelen; + kmsg->msg_flags = msg->msg_flags; + kmsg->msg_namelen = msg->msg_namelen; - if (!msg.msg_name) + if (!msg->msg_name) kmsg->msg_namelen = 0; if (kmsg->msg_namelen < 0) @@ -57,15 +52,15 @@ int __get_compat_msghdr(struct msghdr *kmsg, kmsg->msg_namelen = sizeof(struct sockaddr_storage); kmsg->msg_control_is_user = true; - kmsg->msg_control_user = compat_ptr(msg.msg_control); - kmsg->msg_controllen = msg.msg_controllen; + kmsg->msg_control_user = compat_ptr(msg->msg_control); + kmsg->msg_controllen = msg->msg_controllen; if (save_addr) - *save_addr = compat_ptr(msg.msg_name); + *save_addr = compat_ptr(msg->msg_name); - if (msg.msg_name && kmsg->msg_namelen) { + if (msg->msg_name && kmsg->msg_namelen) { if (!save_addr) { - err = move_addr_to_kernel(compat_ptr(msg.msg_name), + err = move_addr_to_kernel(compat_ptr(msg->msg_name), kmsg->msg_namelen, kmsg->msg_name); if (err < 0) @@ -76,12 +71,10 @@ int __get_compat_msghdr(struct msghdr *kmsg, kmsg->msg_namelen = 0; } - if (msg.msg_iovlen > UIO_MAXIOV) + if (msg->msg_iovlen > UIO_MAXIOV) return -EMSGSIZE; kmsg->msg_iocb = NULL; - *ptr = msg.msg_iov; - *len = msg.msg_iovlen; return 0; } @@ -90,15 +83,17 @@ int get_compat_msghdr(struct msghdr *kmsg, struct sockaddr __user **save_addr, struct iovec **iov) { - compat_uptr_t ptr; - compat_size_t len; + struct compat_msghdr msg; ssize_t err; - err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len); + if (copy_from_user(&msg, umsg, sizeof(*umsg))) + return -EFAULT; + + err = __get_compat_msghdr(kmsg, umsg, save_addr); if (err) return err; - err = import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr), len, + err = import_iovec(save_addr ? READ : WRITE, compat_ptr(msg.msg_iov), msg.msg_iovlen, UIO_FASTIOV, iov, &kmsg->msg_iter); return err < 0 ? err : 0; } -- cgit