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https://github.com/Divested-Mobile/DivestOS-Build.git
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49 lines
1.9 KiB
Diff
49 lines
1.9 KiB
Diff
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From 677e806da4d916052585301785d847c3b3e6186a Mon Sep 17 00:00:00 2001
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From: Andy Whitcroft <apw@canonical.com>
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Date: Wed, 22 Mar 2017 07:29:31 +0000
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Subject: xfrm_user: validate XFRM_MSG_NEWAE XFRMA_REPLAY_ESN_VAL replay_window
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When a new xfrm state is created during an XFRM_MSG_NEWSA call we
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validate the user supplied replay_esn to ensure that the size is valid
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and to ensure that the replay_window size is within the allocated
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buffer. However later it is possible to update this replay_esn via a
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XFRM_MSG_NEWAE call. There we again validate the size of the supplied
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buffer matches the existing state and if so inject the contents. We do
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not at this point check that the replay_window is within the allocated
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memory. This leads to out-of-bounds reads and writes triggered by
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netlink packets. This leads to memory corruption and the potential for
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priviledge escalation.
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We already attempt to validate the incoming replay information in
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xfrm_new_ae() via xfrm_replay_verify_len(). This confirms that the user
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is not trying to change the size of the replay state buffer which
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includes the replay_esn. It however does not check the replay_window
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remains within that buffer. Add validation of the contained
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replay_window.
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CVE-2017-7184
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Signed-off-by: Andy Whitcroft <apw@canonical.com>
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Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
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Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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---
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net/xfrm/xfrm_user.c | 3 +++
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1 file changed, 3 insertions(+)
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diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
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index 9705c27..cdf887f 100644
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--- a/net/xfrm/xfrm_user.c
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+++ b/net/xfrm/xfrm_user.c
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@@ -415,6 +415,9 @@ static inline int xfrm_replay_verify_len(struct xfrm_replay_state_esn *replay_es
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if (nla_len(rp) < ulen || xfrm_replay_state_esn_len(replay_esn) != ulen)
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return -EINVAL;
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+ if (up->replay_window > up->bmp_len * sizeof(__u32) * 8)
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+ return -EINVAL;
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+
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return 0;
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}
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--
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cgit v1.1
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