On 28 May 2014 18:09, Mimi Zohar <zo...@linux.vnet.ibm.com> wrote:
> Dot prefixed keyring names are supposed to be reserved for the
> kernel, but add_key() calls key_get_type_from_user(), which
> incorrectly verifies the 'type' field, not the 'description' field.
> This patch verifies the 'description' field isn't dot prefixed,
> when creating a new keyring, and removes the dot prefix test in
> key_get_type_from_user().
>
> Reported-by: Dmitry Kasatkin <d.kasat...@samsung.com>
> Cc: David Howells <dhowe...@redhat.com>
> Signed-off-by: Mimi Zohar <zo...@linux.vnet.ibm.com>
> ---
> security/keys/keyctl.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
> index cd5bd0c..9e9a762 100644
> --- a/security/keys/keyctl.c
> +++ b/security/keys/keyctl.c
> @@ -37,8 +37,6 @@ static int key_get_type_from_user(char *type,
> return ret;
> if (ret == 0 || ret >= len)
> return -EINVAL;
> - if (type[0] == '.')
> - return -EPERM;
> type[len - 1] = '\0';
> return 0;
> }
> @@ -87,6 +85,10 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
> kfree(description);
> description = NULL;
> }
> + if (description[0] == '.') {
> + ret = -EPERM;
> + goto error2;
> + }
1. 3 lines above "discription = NULL" will cause kernel oops...
It happens when using empty description... like:
cat x509_ima.der | keyctl padd asymmetric "" keyid
2. It prevents adding trusted keys to ".ima" from user space...
This is NOT what we want... right?
- Dmitry
> }
>
> /* pull the payload in if one was supplied */
> --
> 1.8.1.4
>
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--
Thanks,
Dmitry
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