diff options
| author | Dylan Yudaken <dylany@fb.com> | 2022-07-14 04:02:57 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-07-24 18:39:17 -0600 |
| commit | 72c531f8ef3052c682d39dc21dcb5576afda208c (patch) | |
| tree | fa5f25b57b6ac98b2af9048f4e604d6547d27f37 /io_uring | |
| parent | 7fa875b8e53c288d616234b9daf417b0650ce1cc (diff) | |
| download | lwn-72c531f8ef3052c682d39dc21dcb5576afda208c.tar.gz lwn-72c531f8ef3052c682d39dc21dcb5576afda208c.zip | |
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 <pabeni@redhat.com>
Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220714110258.1336200-3-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/net.c | 17 |
1 files changed, 9 insertions, 8 deletions
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) |