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

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: 's avatarJens Axboe <>
parent 2af3e601
......@@ -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;
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