linux-stable.git/net/xfrm, branch linux-3.2.y

xfrm_user: uncoditionally validate esn replay attribute struct

2018-05-31T23:30:15+00:00

commit d97ca5d714a5334aecadadf696875da40f1fbf3e upstream.

The sanity test added in ecd7918745234 can be bypassed, validation
only occurs if XFRM_STATE_ESN flag is set, but rest of code doesn't care
and just checks if the attribute itself is present.

So always validate.  Alternative is to reject if we have the attribute
without the flag but that would change abi.

Reported-by: syzbot+0ab777c27d2bb7588f73@syzkaller.appspotmail.com
Cc: Mathias Krause 
Fixes: ecd7918745234 ("xfrm_user: ensure user supplied esn replay window is valid")
Fixes: d8647b79c3b7e ("xfrm: Add user interface for esn and big anti-replay windows")
Signed-off-by: Florian Westphal 
Signed-off-by: Steffen Klassert 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

xfrm: Use __skb_queue_tail in xfrm_trans_queue

2018-03-03T15:50:55+00:00

commit d16b46e4fd8bc6063624605f25b8c0835bb1fbe3 upstream.

We do not need locking in xfrm_trans_queue because it is designed
to use per-CPU buffers.  However, the original code incorrectly
used skb_queue_tail which takes the lock.  This patch switches
it to __skb_queue_tail instead.

Reported-and-tested-by: Artem Savkov 
Fixes: acf568ee859f ("xfrm: Reinject transport-mode packets...")
Signed-off-by: Herbert Xu 
Signed-off-by: Steffen Klassert 
Signed-off-by: Ben Hutchings

xfrm: Reinject transport-mode packets through tasklet

2018-03-03T15:50:49+00:00

commit acf568ee859f098279eadf551612f103afdacb4e upstream.

This is an old bugbear of mine:

https://www.mail-archive.com/netdev@vger.kernel.org/msg03894.html

By crafting special packets, it is possible to cause recursion
in our kernel when processing transport-mode packets at levels
that are only limited by packet size.

The easiest one is with DNAT, but an even worse one is where
UDP encapsulation is used in which case you just have to insert
an UDP encapsulation header in between each level of recursion.

This patch avoids this problem by reinjecting tranport-mode packets
through a tasklet.

Fixes: b05e106698d9 ("[IPV4/6]: Netfilter IPsec input hooks")
Signed-off-by: Herbert Xu 
Signed-off-by: Steffen Klassert 
[bwh: Backported to 3.2:
 - netfilter finish callbacks only receive an sk_buff pointer
 - Adjust context]
Signed-off-by: Ben Hutchings

ipsec: Fix aborted xfrm policy dump crash

2018-01-01T20:50:59+00:00

commit 1137b5e2529a8f5ca8ee709288ecba3e68044df2 upstream.

This is a fix for CVE-2017-16939 suitable for older stable branches.
The upstream fix is commit 1137b5e2529a8f5ca8ee709288ecba3e68044df2,
from which the following explanation is taken:

    An independent security researcher, Mohamed Ghannam, has reported
    this vulnerability to Beyond Security's SecuriTeam Secure Disclosure
    program.
    
    The xfrm_dump_policy_done function expects xfrm_dump_policy to
    have been called at least once or it will crash.  This can be
    triggered if a dump fails because the target socket's receive
    buffer is full.

It was not possible to define a 'start' callback for netlink dumps
until Linux 4.5, so instead add a check for the initialisation flag in
the 'done' callback.

Signed-off-by: Ben Hutchings

xfrm_user: fix info leak in build_aevent()

2017-11-11T13:34:33+00:00

commit 931e79d7a7ddee4709c56b39de169a36804589a1 upstream.

The memory reserved to dump the ID of the xfrm state includes a padding
byte in struct xfrm_usersa_id added by the compiler for alignment. To
prevent the heap info leak, memset(0) the sa_id before filling it.

Cc: Jamal Hadi Salim 
Fixes: d51d081d6504 ("[IPSEC]: Sync series - user")
Signed-off-by: Mathias Krause 
Signed-off-by: Steffen Klassert 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

xfrm_user: fix info leak in xfrm_notify_sa()

2017-11-11T13:34:33+00:00

commit 50329c8a340c9dea60d837645fcf13fc36bfb84d upstream.

The memory reserved to dump the ID of the xfrm state includes a padding
byte in struct xfrm_usersa_id added by the compiler for alignment. To
prevent the heap info leak, memset(0) the whole struct before filling
it.

Cc: Herbert Xu 
Fixes: 0603eac0d6b7 ("[IPSEC]: Add XFRMA_SA/XFRMA_POLICY for delete notification")
Signed-off-by: Mathias Krause 
Signed-off-by: Steffen Klassert 
Signed-off-by: Ben Hutchings

xfrm: policy: check policy direction value

2017-09-15T17:30:56+00:00

commit 7bab09631c2a303f87a7eb7e3d69e888673b9b7e upstream.

The 'dir' parameter in xfrm_migrate() is a user-controlled byte which is used
as an array index. This can lead to an out-of-bound access, kernel lockup and
DoS. Add a check for the 'dir' value.

This fixes CVE-2017-11600.

References: https://bugzilla.redhat.com/show_bug.cgi?id=1474928
Fixes: 80c9abaabf42 ("[XFRM]: Extension for dynamic update of endpoint address(es)")
Reported-by: "bo Zhang" 
Signed-off-by: Vladis Dronov 
Signed-off-by: Steffen Klassert 
Signed-off-by: Ben Hutchings

xfrm: fix stack access out of bounds with CONFIG_XFRM_SUB_POLICY

2017-09-15T17:30:40+00:00

commit 9b3eb54106cf6acd03f07cf0ab01c13676a226c2 upstream.

When CONFIG_XFRM_SUB_POLICY=y, xfrm_dst stores a copy of the flowi for
that dst. Unfortunately, the code that allocates and fills this copy
doesn't care about what type of flowi (flowi, flowi4, flowi6) gets
passed. In multiple code paths (from raw_sendmsg, from TCP when
replying to a FIN, in vxlan, geneve, and gre), the flowi that gets
passed to xfrm is actually an on-stack flowi4, so we end up reading
stuff from the stack past the end of the flowi4 struct.

Since xfrm_dst->origin isn't used anywhere following commit
ca116922afa8 ("xfrm: Eliminate "fl" and "pol" args to
xfrm_bundle_ok()."), just get rid of it.  xfrm_dst->partner isn't used
either, so get rid of that too.

Fixes: 9d6ec938019c ("ipv4: Use flowi4 in public route lookup interfaces.")
Signed-off-by: Sabrina Dubroca 
Signed-off-by: Steffen Klassert 
[bwh: Backported to 3.2: deleted code is slightly different]
Signed-off-by: Ben Hutchings

xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder

2017-06-05T20:13:53+00:00

commit f843ee6dd019bcece3e74e76ad9df0155655d0df upstream.

Kees Cook has pointed out that xfrm_replay_state_esn_len() is subject to
wrapping issues.  To ensure we are correctly ensuring that the two ESN
structures are the same size compare both the overall size as reported
by xfrm_replay_state_esn_len() and the internal length are the same.

CVE-2017-7184
Signed-off-by: Andy Whitcroft 
Acked-by: Steffen Klassert 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

xfrm_user: validate XFRM_MSG_NEWAE XFRMA_REPLAY_ESN_VAL replay_window

2017-06-05T20:13:53+00:00

commit 677e806da4d916052585301785d847c3b3e6186a upstream.

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 
Acked-by: Steffen Klassert 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings