diff options
| author | Dylan Yudaken <dylany@fb.com> | 2022-06-30 12:12:22 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-07-25 03:39:16 +0300 |
| commit | 5702196e7d9d1232c41769e197eb33ba78a9b463 (patch) | |
| tree | a408c2f25cb698e9f7804e20ed7893b4ac123fa6 /io_uring | |
| parent | 32f3c434b14238a2eee0c726a1918de58c07faf6 (diff) | |
| download | linux-5702196e7d9d1232c41769e197eb33ba78a9b463.tar.xz | |
io_uring: allow iov_len = 0 for recvmsg and buffer select
When using BUFFER_SELECT there is no technical requirement that the user
actually provides iov, and this removes one copy_from_user call.
So allow iov_len to be 0.
Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220630091231.1456789-4-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/net.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/io_uring/net.c b/io_uring/net.c index b77bfbfb0816..06eaef9f97be 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -300,12 +300,18 @@ static int __io_recvmsg_copy_hdr(struct io_kiocb *req, return ret; if (req->flags & REQ_F_BUFFER_SELECT) { - if (iov_len > 1) + if (iov_len == 0) { + sr->len = iomsg->fast_iov[0].iov_len = 0; + iomsg->fast_iov[0].iov_base = NULL; + iomsg->free_iov = NULL; + } else if (iov_len > 1) { return -EINVAL; - if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov))) - return -EFAULT; - sr->len = iomsg->fast_iov[0].iov_len; - iomsg->free_iov = NULL; + } else { + if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov))) + return -EFAULT; + sr->len = iomsg->fast_iov[0].iov_len; + iomsg->free_iov = NULL; + } } else { iomsg->free_iov = iomsg->fast_iov; ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV, |