From 6d2f75a0cf3048ef38c48493f66a923353bf664b Mon Sep 17 00:00:00 2001 From: Dylan Yudaken Date: Fri, 8 Jul 2022 11:18:36 -0700 Subject: io_uring: support 0 length iov in buffer select in compat Match up work done in "io_uring: allow iov_len = 0 for recvmsg and buffer select", but for compat code path. Fixes: a68caad69ce5 ("io_uring: allow iov_len = 0 for recvmsg and buffer select") Signed-off-by: Dylan Yudaken Link: https://lore.kernel.org/r/20220708181838.1495428-3-dylany@fb.com Signed-off-by: Jens Axboe --- io_uring/net.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'io_uring') diff --git a/io_uring/net.c b/io_uring/net.c index eb939899e9c5..dc9190eafbe7 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -382,16 +382,21 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, if (req->flags & REQ_F_BUFFER_SELECT) { compat_ssize_t clen; - if (len > 1) - return -EINVAL; - if (!access_ok(uiov, sizeof(*uiov))) - return -EFAULT; - if (__get_user(clen, &uiov->iov_len)) - return -EFAULT; - if (clen < 0) + if (len == 0) { + sr->len = 0; + iomsg->free_iov = NULL; + } else if (len > 1) { return -EINVAL; - sr->len = clen; - iomsg->free_iov = NULL; + } else { + if (!access_ok(uiov, sizeof(*uiov))) + return -EFAULT; + if (__get_user(clen, &uiov->iov_len)) + return -EFAULT; + if (clen < 0) + return -EINVAL; + sr->len = clen; + iomsg->free_iov = NULL; + } } else { iomsg->free_iov = iomsg->fast_iov; ret = __import_iovec(READ, (struct iovec __user *)uiov, len, -- cgit v1.2.3