| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.15 112/139] aio: fix kernel memory disclosure in io_getevents() introduced in v3.10 | Date | Sat, 28 Jun 2014 10:47:53 -0700 |
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3.15-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin LaHaise <bcrl@kvack.org>
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.
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Kent Overstreet <kmo@daterainc.com> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/aio.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/fs/aio.c +++ b/fs/aio.c @@ -1063,6 +1063,9 @@ static long aio_read_events_ring(struct if (head == tail) goto out; + head %= ctx->nr_events; + tail %= ctx->nr_events; + while (ret < nr) { long avail; struct io_event *ev;
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