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| author | Ryan Ware <ware@linux.intel.com> | 2016-02-11 15:58:44 -0800 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2016-04-23 09:24:43 +0200 |
| commit | afe5a791d374e50a06ada7f4eda4e921e1b77996 (patch) | |
| tree | 6d53aebdc3ac02a7e08b1cc92ec9822fc78e6bdd | |
| parent | d68e944a8fcb2c6212b38064771c9f5af7b0b92c (diff) | |
| download | linux-stable-afe5a791d374e50a06ada7f4eda4e921e1b77996.tar.gz linux-stable-afe5a791d374e50a06ada7f4eda4e921e1b77996.tar.bz2 linux-stable-afe5a791d374e50a06ada7f4eda4e921e1b77996.zip | |
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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | security/integrity/evm/evm_main.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index d43b62c4a8e5..5bf01c8648a8 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -21,6 +21,7 @@ #include <linux/integrity.h> #include <linux/evm.h> #include <crypto/hash.h> +#include <crypto/algapi.h> #include "evm.h" int evm_initialized; @@ -132,7 +133,7 @@ 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; |