UPSTREAM: xfrm_user: validate XFRM_MSG_NEWAE XFRMA_REPLAY_ESN_VAL replay_window
When a new xfrm state is created during an XFRM_MSG_NEWSA call we
validate the user supplied replay_esn to ensure that the size is valid
and to ensure that the replay_window size is within the allocated
buffer. However later it is possible to update this replay_esn via a
XFRM_MSG_NEWAE call. There we again validate the size of the supplied
buffer matches the existing state and if so inject the contents. We do
not at this point check that the replay_window is within the allocated
memory. This leads to out-of-bounds reads and writes triggered by
netlink packets. This leads to memory corruption and the potential for
priviledge escalation.
We already attempt to validate the incoming replay information in
xfrm_new_ae() via xfrm_replay_verify_len(). This confirms that the user
is not trying to change the size of the replay state buffer which
includes the replay_esn. It however does not check the replay_window
remains within that buffer. Add validation of the contained
replay_window.
CVE-2017-7184
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Ulanov <andreyu@google.com>
(cherry-picked from 677e806da4d916052585301785d847c3b3e6186a)
BUG=b:36733546
TEST=kernel compiles
Change-Id: Id186c377a19805e946e87cdf4f411f48ace780c8
Reviewed-on: https://chromium-review.googlesource.com/462458
Commit-Ready: Andrey Ulanov <andreyu@google.com>
Tested-by: Andrey Ulanov <andreyu@google.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
(cherry picked from commit 78cccdb696702a3a093733234ddac2cb86958642)
Reviewed-on: https://chromium-review.googlesource.com/465599
Commit-Queue: Andrey Ulanov <andreyu@google.com>
1 file changed