On 23 October 2014 18:40, Jan Kara <j...@suse.cz> wrote:
> On Thu 23-10-14 16:47:17, Dmitry Kasatkin wrote:
>> ima_inode_setxattr() can be called with no value. Function does not
>> check the length so that following command can be used to produce
>> kernel oops: setfattr -n security.ima FOO. This patch fixes it.
>>
> ..
>>
>> Reported-by: Jan Kara <j...@suse.cz>
>> Signed-off-by: Dmitry Kasatkin <d.kasat...@samsung.com>
>> ---
>> security/integrity/ima/ima_appraise.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/security/integrity/ima/ima_appraise.c
>> b/security/integrity/ima/ima_appraise.c
>> index 5b845af..f07aacd 100644
>> --- a/security/integrity/ima/ima_appraise.c
>> +++ b/security/integrity/ima/ima_appraise.c
>> @@ -378,6 +378,8 @@ int ima_inode_setxattr(struct dentry *dentry, const char
>> *xattr_name,
>> result = ima_protect_xattr(dentry, xattr_name, xattr_value,
>> xattr_value_len);
>> if (result == 1) {
>> + if (!xattr_value_len)
>> + return -EINVAL;
> Wouldn't it be safer to return EINVAL whenever xattr_value_len !=
> sizeof(evm_ima_xattr_data)?
In this function we only use first byte to identify attribute type.
sizeof(evm_ima_xattr_data) is SHA1_DIGEST_SIZE + 1.
But IMA may use any other algorithm where digest size is different.
- Dmitry
>
> Honza
>> ima_reset_appraise_flags(dentry->d_inode,
>> (xvalue->type == EVM_IMA_XATTR_DIGSIG) ? 1 : 0);
>> result = 0;
>> --
>> 1.9.1
>>
> --
> Jan Kara <j...@suse.cz>
> SUSE Labs, CR
--
Thanks,
Dmitry
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
