From: Jens Axboe Date: Mon, 17 Mar 2008 08:04:59 +0000 (+0100) Subject: relay: fix subbuf_splice_actor() adding too many pages X-Git-Tag: firefly_0821_release~21976^2~1 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=16d54669427069ef2823752c365d695b0cc4748f;p=firefly-linux-kernel-4.4.55.git 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 --- diff --git a/kernel/relay.c b/kernel/relay.c index d080b9d161a7..4c035a8a248c 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -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;