diff options
| author | Dmitry Kasatkin <dmitry.kasatkin@gmail.com> | 2014-10-01 21:43:08 +0300 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.vnet.ibm.com> | 2014-10-07 14:32:53 -0400 |
| commit | c2baec7ffaf6a2c15e03028ed9ef82a92cc49a94 (patch) | |
| tree | a08f5716f4c0dd61f451e488a557d66a748c00da /security | |
| parent | d16a8585d3715ef161cc9858b50ea5d3c8b6079b (diff) | |
| download | linux-rpi3-c2baec7ffaf6a2c15e03028ed9ef82a92cc49a94.tar.gz linux-rpi3-c2baec7ffaf6a2c15e03028ed9ef82a92cc49a94.tar.bz2 linux-rpi3-c2baec7ffaf6a2c15e03028ed9ef82a92cc49a94.zip | |
evm: skip replacing EVM signature with HMAC on read-only filesystem
If filesystem is mounted read-only or file is immutable, updating
xattr will fail. This is a usual case during early boot until
filesystem is remount read-write. This patch verifies conditions
to skip unnecessary attempt to calculate HMAC and set xattr.
Changes in v2:
* indention changed according to Lindent (requested by Mimi)
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/evm/evm_main.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 9685af330de5..b392fe614738 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -162,9 +162,14 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, (const char *)xattr_data, xattr_len, calc.digest, sizeof(calc.digest)); if (!rc) { - /* we probably want to replace rsa with hmac here */ - evm_update_evmxattr(dentry, xattr_name, xattr_value, - xattr_value_len); + /* Replace RSA with HMAC if not mounted readonly and + * not immutable + */ + if (!IS_RDONLY(dentry->d_inode) && + !IS_IMMUTABLE(dentry->d_inode)) + evm_update_evmxattr(dentry, xattr_name, + xattr_value, + xattr_value_len); } break; default: |