| Message ID | 1455706132-15474-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 41f32259437c..c9db5ab63ad2 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -24,6 +24,7 @@ #include <linux/evm.h> #include <linux/magic.h> #include <crypto/hash.h> +#include <crypto/algapi.h> #include "evm.h" int evm_initialized; @@ -148,7 +149,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, xattr_value_len, calc.digest); if (rc) break; - rc = memcmp(xattr_data->digest, calc.digest, + rc = crypto_memneq(xattr_data->digest, calc.digest, sizeof(calc.digest)); if (rc) rc = -EINVAL;
This is a note to let you know that I have just added a patch titled EVM: Use crypto_memneq() for digest comparisons to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt25. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From 50e2fe0e98fffd08cb81b1785174db30902271c6 Mon Sep 17 00:00:00 2001 From: Ryan Ware <ware@linux.intel.com> Date: Thu, 11 Feb 2016 15:58:44 -0800 Subject: EVM: Use crypto_memneq() for digest comparisons commit 613317bd212c585c20796c10afe5daaa95d4b0a1 upstream. This patch fixes vulnerability CVE-2016-2085. The problem exists because the vm_verify_hmac() function includes a use of memcmp(). Unfortunately, this allows timing side channel attacks; specifically a MAC forgery complexity drop from 2^128 to 2^12. This patch changes the memcmp() to the cryptographically safe crypto_memneq(). Reported-by: Xiaofei Rex Guo <xiaofei.rex.guo@intel.com> Signed-off-by: Ryan Ware <ware@linux.intel.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: James Morris <james.l.morris@oracle.com> Cc: Moritz Muehlenhoff <jmm@inutil.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- security/integrity/evm/evm_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)