[PATCH v2 for-next 01/12] io_uring: allow 0 length for buffer select

From: Dylan Yudaken
Date: Thu Jun 30 2022 - 05:18:49 EST


If user gives 0 for length, we can set it from the available buffer size.

Signed-off-by: Dylan Yudaken <dylany@xxxxxx>
---
io_uring/kbuf.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
index 8e4f1e8aaf4a..4ed5102461bf 100644
--- a/io_uring/kbuf.c
+++ b/io_uring/kbuf.c
@@ -115,7 +115,7 @@ static void __user *io_provided_buffer_select(struct io_kiocb *req, size_t *len,

kbuf = list_first_entry(&bl->buf_list, struct io_buffer, list);
list_del(&kbuf->list);
- if (*len > kbuf->len)
+ if (*len == 0 || *len > kbuf->len)
*len = kbuf->len;
req->flags |= REQ_F_BUFFER_SELECTED;
req->kbuf = kbuf;
@@ -145,7 +145,7 @@ static void __user *io_ring_buffer_select(struct io_kiocb *req, size_t *len,
buf = page_address(bl->buf_pages[index]);
buf += off;
}
- if (*len > buf->len)
+ if (*len == 0 || *len > buf->len)
*len = buf->len;
req->flags |= REQ_F_BUFFER_RING;
req->buf_list = bl;
--
2.30.2