Commit 16d54669 authored by Jens Axboe's avatar Jens Axboe
Browse files

relay: fix subbuf_splice_actor() adding too many pages 



If subbuf_pages was larger than the max number of pages the pipe
buffer will hold, subbuf_splice_actor() would happily go beyond
the array size.

Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 2af3e601

kernel/relay.c

+3 −2
Original line number Diff line number Diff line
@@ -1066,7 +1066,7 @@ static int subbuf_splice_actor(struct file *in, 
			       unsigned int flags,

			       int *nonpad_ret)

{

	unsigned int pidx, poff, total_len, subbuf_pages, ret;

	unsigned int pidx, poff, total_len, subbuf_pages, nr_pages, ret;

	struct rchan_buf *rbuf = in->private_data;

	unsigned int subbuf_size = rbuf->chan->subbuf_size;

	uint64_t pos = (uint64_t) *ppos;
@@ -1097,8 +1097,9 @@ static int subbuf_splice_actor(struct file *in, 
	subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT;

	pidx = (read_start / PAGE_SIZE) % subbuf_pages;

	poff = read_start & ~PAGE_MASK;

	nr_pages = min_t(unsigned int, subbuf_pages, PIPE_BUFFERS);



	for (total_len = 0; spd.nr_pages < subbuf_pages; spd.nr_pages++) {

	for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) {

		unsigned int this_len, this_end, private;

		unsigned int cur_pos = read_start + total_len;