From: Benjamin LaHaise Date: Tue, 24 Jun 2014 17:32:51 +0000 (-0400) Subject: aio: fix kernel memory disclosure in io_getevents() introduced in v3.10 X-Git-Tag: v3.10.46~18 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d36db46c2cba973557eb6138d22210c4e0cf17d6;p=platform%2Fkernel%2Flinux-stable.git aio: fix kernel memory disclosure in io_getevents() introduced in v3.10 commit edfbbf388f293d70bf4b7c0bc38774d05e6f711a upstream. 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. [jmoyer@redhat.com: backported to 3.10] Signed-off-by: Benjamin LaHaise Signed-off-by: Jeff Moyer Cc: Mateusz Guzik Cc: Petr Matousek Cc: Kent Overstreet Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/aio.c b/fs/aio.c index 8d2c997..ded94c4 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -717,6 +717,8 @@ static long aio_read_events_ring(struct kioctx *ctx, if (head == ctx->tail) goto out; + head %= ctx->nr_events; + while (ret < nr) { long avail; struct io_event *ev;