From 97da4a537924d87e2261773f3ac9365abb191fc9 Mon Sep 17 00:00:00 2001 From: Dylan Yudaken Date: Mon, 13 Jun 2022 03:11:55 -0700 Subject: io_uring: fix index calculation When indexing into a provided buffer ring, do not subtract 1 from the index. Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers") Signed-off-by: Dylan Yudaken Link: https://lore.kernel.org/r/20220613101157.3687-2-dylany@fb.com Reviewed-by: Hao Xu Signed-off-by: Jens Axboe --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 3aab4182fd89..9cf9aff51b70 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3888,7 +3888,7 @@ static void __user *io_ring_buffer_select(struct io_kiocb *req, size_t *len, buf = &br->bufs[head]; } else { int off = head & (IO_BUFFER_LIST_BUF_PER_PAGE - 1); - int index = head / IO_BUFFER_LIST_BUF_PER_PAGE - 1; + int index = head / IO_BUFFER_LIST_BUF_PER_PAGE; buf = page_address(bl->buf_pages[index]); buf += off; } -- cgit v1.2.3