[PATCH 5.7 054/163] io_uring: re-set iov base/len for buffer select retry

From: Greg Kroah-Hartman
Date: Tue Jun 16 2020 - 11:45:47 EST


From: Jens Axboe <axboe@xxxxxxxxx>

commit dddb3e26f6d88c5344d28cb5ff9d3d6fa05c4f7a upstream.

We already have the buffer selected, but we should set the iter list
again.

Cc: stable@xxxxxxxxxxxxxxx # v5.7
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/io_uring.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2333,8 +2333,14 @@ static ssize_t __io_iov_buffer_select(st
static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
bool needs_lock)
{
- if (req->flags & REQ_F_BUFFER_SELECTED)
+ if (req->flags & REQ_F_BUFFER_SELECTED) {
+ struct io_buffer *kbuf;
+
+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
+ iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
+ iov[0].iov_len = kbuf->len;
return 0;
+ }
if (!req->rw.len)
return 0;
else if (req->rw.len > 1)