| Date | Fri, 21 Mar 2008 15:44:06 -0700 | From | Chris Wright <> | Subject | [patch 76/76] relay: fix subbuf_splice_actor() adding too many pages |
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-stable review patch. If anyone has any objections, please let us know. ---------------------
From: Jens Axboe <jens.axboe@oracle.com>
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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
--- kernel/relay.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/kernel/relay.c +++ b/kernel/relay.c @@ -1072,7 +1072,7 @@ static int subbuf_splice_actor(struct fi 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; @@ -1103,8 +1103,9 @@ static int subbuf_splice_actor(struct fi 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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