Messages in this thread Patch in this message | | | Date | Tue, 24 Jun 2014 14:02:17 -0400 | From | Benjamin LaHaise <> | Subject | [PATCH 2/2] aio: fix kernel memory disclosure in io_getevents() introduced in v3.10 |
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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> Cc: stable@vger.kernel.org --- fs/aio.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/aio.c b/fs/aio.c index 6a9c7e4..955947e 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; -- 1.8.2.1
-- "Thought is the essence of where you are now."
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