From edfbbf388f293d70bf4b7c0bc38774d05e6f711a Mon Sep 17 00:00:00 2001 From: Benjamin LaHaise Date: Tue, 24 Jun 2014 13:32:51 -0400 Subject: aio: fix kernel memory disclosure in io_getevents() introduced in v3.10 A kernel memory disclosure was introduced in aio_read_events_ring() in v3.10 by commit a31ad380bed817aa25f8830ad23e1a0480fef797. The changes made to aio_read_events_ring() failed to correctly limit the index into ctx->ring_pages[], allowing an attacked to cause the subsequent kmap() of an arbitrary page with a copy_to_user() to copy the contents into userspace. This vulnerability has been assigned CVE-2014-0206. Thanks to Mateusz and Petr for disclosing this issue. This patch applies to v3.12+. A separate backport is needed for 3.10/3.11. Signed-off-by: Benjamin LaHaise Cc: Mateusz Guzik Cc: Petr Matousek Cc: Kent Overstreet Cc: Jeff Moyer Cc: stable@vger.kernel.org --- fs/aio.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/aio.c') diff --git a/fs/aio.c b/fs/aio.c index 6a9c7e489adf..955947ef3e02 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1063,6 +1063,9 @@ static long aio_read_events_ring(struct kioctx *ctx, if (head == tail) goto out; + head %= ctx->nr_events; + tail %= ctx->nr_events; + while (ret < nr) { long avail; struct io_event *ev; -- cgit v1.2.3-55-g7522