| Message ID | 20200618160133.937-4-roberto.sassu@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/11] evm: Execute evm_inode_init_security() only when the HMAC key is loaded | expand |
On Thu, 2020-06-18 at 18:01 +0200, Roberto Sassu wrote: > This patch checks the size for the EVM_IMA_XATTR_DIGSIG and > EVM_XATTR_PORTABLE_DIGSIG types to ensure that the algorithm is read from > the buffer returned by vfs_getxattr_alloc(). > > Cc: stable@vger.kernel.org # 4.19.x > Fixes: 5feeb61183dde ("evm: Allow non-SHA1 digital signatures") > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 744c105b48d1..4e9f5e8b21d5 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -181,6 +181,12 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, break; case EVM_IMA_XATTR_DIGSIG: case EVM_XATTR_PORTABLE_DIGSIG: + /* accept xattr with non-empty signature field */ + if (xattr_len <= sizeof(struct signature_v2_hdr)) { + evm_status = INTEGRITY_FAIL; + goto out; + } + hdr = (struct signature_v2_hdr *)xattr_data; digest.hdr.algo = hdr->hash_algo; rc = evm_calc_hash(dentry, xattr_name, xattr_value,
This patch checks the size for the EVM_IMA_XATTR_DIGSIG and EVM_XATTR_PORTABLE_DIGSIG types to ensure that the algorithm is read from the buffer returned by vfs_getxattr_alloc(). Cc: stable@vger.kernel.org # 4.19.x Fixes: 5feeb61183dde ("evm: Allow non-SHA1 digital signatures") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> --- security/integrity/evm/evm_main.c | 6 ++++++ 1 file changed, 6 insertions(+)