[PATCH] io_uring: fix mm use with IORING_OP_{READ,WRITE}

From: Pavel Begunkov
Date: Wed Feb 05 2020 - 10:47:07 EST


IORING_OP_{READ,WRITE} need mm to access user buffers, hence
req->has_user check should go for them as well. Move the corresponding
imports past the check.

Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
fs/io_uring.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index edb00ae2619b..f00c2c9c67c0 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2038,13 +2038,6 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
if (req->rw.kiocb.private)
return -EINVAL;

- if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
- ssize_t ret;
- ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
- *iovec = NULL;
- return ret;
- }
-
if (req->io) {
struct io_async_rw *iorw = &req->io->rw;

@@ -2058,6 +2051,13 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
if (!req->has_user)
return -EFAULT;

+ if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
+ ssize_t ret;
+ ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
+ *iovec = NULL;
+ return ret;
+ }
+
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV,
--
2.24.0