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| author |   Seth Forshee <seth.forshee@canonical.com> | 2016-08-01 08:19:10 -0500 |
|---|---|---|
| committer |   Mimi Zohar <zohar@linux.vnet.ibm.com> | 2016-11-13 22:50:11 -0500 |
| commit | b4bfec7f4a86424b114f94f41c4e1841ec102df3 (patch) | |
| tree | 9f4a668c3d28ef3de0743d3dda285829b38a85a3 /security/integrity/evm | |
| parent | Doc: security: keys-trusted: drop duplicate blobauth entry (diff) | |
| download | linux-dev-b4bfec7f4a86424b114f94f41c4e1841ec102df3.tar.xz linux-dev-b4bfec7f4a86424b114f94f41c4e1841ec102df3.zip | |
security/integrity: Harden against malformed xattrs
In general the handling of IMA/EVM xattrs is good, but I found
a few locations where either the xattr size or the value of the
type field in the xattr are not checked. Add a few simple checks
to these locations to prevent malformed or malicious xattrs from
causing problems.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Diffstat (limited to 'security/integrity/evm')
| -rw-r--r-- | security/integrity/evm/evm_main.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index ba8615576d4d..e2ed498c0f5f 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -145,6 +145,10 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, /* check value type */ switch (xattr_data->type) { case EVM_XATTR_HMAC: + if (xattr_len != sizeof(struct evm_ima_xattr_data)) { + evm_status = INTEGRITY_FAIL; + goto out; + } rc = evm_calc_hmac(dentry, xattr_name, xattr_value, xattr_value_len, calc.digest); if (rc) |