[linux] 02/07: Add patches for CVE-2017-7184

Wed Apr 19 17:58:40 UTC 2017

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benh pushed a commit to branch jessie
in repository linux.

commit 9b8ac5702b6fab14c4eafbd8a603cdcf4e5ad3c9
Author: Ben Hutchings <ben at decadent.org.uk>
Date:   Wed Apr 19 18:34:15 2017 +0100

    Add patches for CVE-2017-7184
---
 debian/changelog                                   |  3 ++
 ...e-xfrm_msg_newae-incoming-esn-size-harder.patch | 34 ++++++++++++++++
 ..._newae-xfrma_replay_esn_val-replay_window.patch | 45 ++++++++++++++++++++++
 debian/patches/series                              |  2 +
 4 files changed, 84 insertions(+)

diff --git a/debian/changelog b/debian/changelog
index 5ae11b0..969994f 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -595,6 +595,9 @@ linux (3.16.43-1) UNRELEASED; urgency=medium
     - mm: split ET_DYN ASLR from mmap ASLR
     - mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE
   * ping: implement proper locking (CVE-2017-2671)
+  * xfrm_user: validate XFRM_MSG_NEWAE XFRMA_REPLAY_ESN_VAL replay_window
+    (CVE-2017-7184)
+  * xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder (CVE-2017-7184)
 
   [ Salvatore Bonaccorso ]
   * sunrpc: fix refcounting problems with auth_gss messages.
diff --git a/debian/patches/bugfix/all/xfrm_user-validate-xfrm_msg_newae-incoming-esn-size-harder.patch b/debian/patches/bugfix/all/xfrm_user-validate-xfrm_msg_newae-incoming-esn-size-harder.patch
new file mode 100644
index 0000000..116d3e4
--- /dev/null
+++ b/debian/patches/bugfix/all/xfrm_user-validate-xfrm_msg_newae-incoming-esn-size-harder.patch
@@ -0,0 +1,34 @@
+From: Andy Whitcroft <apw at canonical.com>
+Date: Thu, 23 Mar 2017 07:45:44 +0000
+Subject: [2/2] xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder
+Origin: https://git.kernel.org/linus/f843ee6dd019bcece3e74e76ad9df0155655d0df
+Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2017-7184
+
+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 <apw at canonical.com>
+Acked-by: Steffen Klassert <steffen.klassert at secunet.com>
+Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
+---
+ net/xfrm/xfrm_user.c | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+--- a/net/xfrm/xfrm_user.c
++++ b/net/xfrm/xfrm_user.c
+@@ -387,7 +387,11 @@ static inline int xfrm_replay_verify_len
+ 	up = nla_data(rp);
+ 	ulen = xfrm_replay_state_esn_len(up);
+ 
+-	if (nla_len(rp) < ulen || xfrm_replay_state_esn_len(replay_esn) != ulen)
++	/* Check the overall length and the internal bitmap length to avoid
++	 * potential overflow. */
++	if (nla_len(rp) < ulen ||
++	    xfrm_replay_state_esn_len(replay_esn) != ulen ||
++	    replay_esn->bmp_len != up->bmp_len)
+ 		return -EINVAL;
+ 
+ 	if (up->replay_window > up->bmp_len * sizeof(__u32) * 8)
diff --git a/debian/patches/bugfix/all/xfrm_user-validate-xfrm_msg_newae-xfrma_replay_esn_val-replay_window.patch b/debian/patches/bugfix/all/xfrm_user-validate-xfrm_msg_newae-xfrma_replay_esn_val-replay_window.patch
new file mode 100644
index 0000000..5ef3ea6
--- /dev/null
+++ b/debian/patches/bugfix/all/xfrm_user-validate-xfrm_msg_newae-xfrma_replay_esn_val-replay_window.patch
@@ -0,0 +1,45 @@
+From: Andy Whitcroft <apw at canonical.com>
+Date: Wed, 22 Mar 2017 07:29:31 +0000
+Subject: [1/2] xfrm_user: validate XFRM_MSG_NEWAE XFRMA_REPLAY_ESN_VAL
+ replay_window
+Origin: https://git.kernel.org/linus/677e806da4d916052585301785d847c3b3e6186a
+Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2017-7184
+
+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 at canonical.com>
+Acked-by: Steffen Klassert <steffen.klassert at secunet.com>
+Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
+---
+ net/xfrm/xfrm_user.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/net/xfrm/xfrm_user.c
++++ b/net/xfrm/xfrm_user.c
+@@ -390,6 +390,9 @@ static inline int xfrm_replay_verify_len
+ 	if (nla_len(rp) < ulen || xfrm_replay_state_esn_len(replay_esn) != ulen)
+ 		return -EINVAL;
+ 
++	if (up->replay_window > up->bmp_len * sizeof(__u32) * 8)
++		return -EINVAL;
++
+ 	return 0;
+ }
+ 
diff --git a/debian/patches/series b/debian/patches/series
index 1212e47..2a65175 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -676,6 +676,8 @@ bugfix/all/pie-aslr/mm-fold-arch_randomize_brk-into-arch_has_elf_randomi.patch
 bugfix/all/timer-restrict-timer_stats-to-initial-pid-namespace.patch
 bugfix/all/mbcache-reschedule-before-restarting-iteration-in-mb_cache_entry_alloc.patch
 bugfix/all/ping-implement-proper-locking.patch
+bugfix/all/xfrm_user-validate-xfrm_msg_newae-xfrma_replay_esn_val-replay_window.patch
+bugfix/all/xfrm_user-validate-xfrm_msg_newae-incoming-esn-size-harder.patch
 
 # Fix ABI changes
 debian/of-fix-abi-changes.patch

-- 
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