6.15-stable review patch. If anyone has any objections, please let me know.
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From: Jens Axboe axboe@kernel.dk
commit 26ec15e4b0c1d7b25214d9c0be1d50492e2f006c upstream.
If peeking a bunch of buffers, normally io_ring_buffers_peek() will truncate the end buffer. This isn't optimal as presumably more data will be arriving later, and hence it's better to stop with the last full buffer rather than truncate the end buffer.
Cc: stable@vger.kernel.org Fixes: 35c8711c8fc4 ("io_uring/kbuf: add helpers for getting/peeking multiple buffers") Reported-by: Christian Mazakas christian.mazakas@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/kbuf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -270,8 +270,11 @@ static int io_ring_buffers_peek(struct i /* truncate end piece, if needed, for non partial buffers */ if (len > arg->max_len) { len = arg->max_len; - if (!(bl->flags & IOBL_INC)) + if (!(bl->flags & IOBL_INC)) { + if (iov != arg->iovs) + break; buf->len = len; + } }
iov->iov_base = u64_to_user_ptr(buf->addr);