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: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe 2008-03-17 09:04:59 +01:00
parent 2af3e6017e
commit 16d5466942

View file

@ -1066,7 +1066,7 @@ static int subbuf_splice_actor(struct file *in,
unsigned int flags, unsigned int flags,
int *nonpad_ret) 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; struct rchan_buf *rbuf = in->private_data;
unsigned int subbuf_size = rbuf->chan->subbuf_size; unsigned int subbuf_size = rbuf->chan->subbuf_size;
uint64_t pos = (uint64_t) *ppos; 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; subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT;
pidx = (read_start / PAGE_SIZE) % subbuf_pages; pidx = (read_start / PAGE_SIZE) % subbuf_pages;
poff = read_start & ~PAGE_MASK; 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 this_len, this_end, private;
unsigned int cur_pos = read_start + total_len; unsigned int cur_pos = read_start + total_len;