47 lines
1.4 KiB
Diff
47 lines
1.4 KiB
Diff
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Bugzilla: 1112975
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Upstream-status: 3.16 and CC'd to stable
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From edfbbf388f293d70bf4b7c0bc38774d05e6f711a Mon Sep 17 00:00:00 2001
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From: Benjamin LaHaise <bcrl@kvack.org>
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Date: Tue, 24 Jun 2014 13:32:51 -0400
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Subject: [PATCH] aio: fix kernel memory disclosure in io_getevents()
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introduced in v3.10
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A kernel memory disclosure was introduced in aio_read_events_ring() in v3.10
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by commit a31ad380bed817aa25f8830ad23e1a0480fef797. The changes made to
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aio_read_events_ring() failed to correctly limit the index into
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ctx->ring_pages[], allowing an attacked to cause the subsequent kmap() of
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an arbitrary page with a copy_to_user() to copy the contents into userspace.
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This vulnerability has been assigned CVE-2014-0206. Thanks to Mateusz and
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Petr for disclosing this issue.
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This patch applies to v3.12+. A separate backport is needed for 3.10/3.11.
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Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
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Cc: Mateusz Guzik <mguzik@redhat.com>
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Cc: Petr Matousek <pmatouse@redhat.com>
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Cc: Kent Overstreet <kmo@daterainc.com>
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Cc: Jeff Moyer <jmoyer@redhat.com>
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Cc: stable@vger.kernel.org
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---
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fs/aio.c | 3 +++
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1 file changed, 3 insertions(+)
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diff --git a/fs/aio.c b/fs/aio.c
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index 6a9c7e489adf..955947ef3e02 100644
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--- a/fs/aio.c
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+++ b/fs/aio.c
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@@ -1063,6 +1063,9 @@ static long aio_read_events_ring(struct kioctx *ctx,
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if (head == tail)
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goto out;
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+ head %= ctx->nr_events;
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+ tail %= ctx->nr_events;
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+
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while (ret < nr) {
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long avail;
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struct io_event *ev;
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--
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1.9.3
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