On 30 May 2014 22:12, Mimi Zohar <zo...@linux.vnet.ibm.com> wrote: > On Fri, 2014-05-30 at 21:24 +0300, Dmitry Kasatkin wrote: >> On 30 May 2014 20:58, "Mimi Zohar" <zo...@linux.vnet.ibm.com> wrote: >> > >> > On Fri, 2014-05-30 at 18:58 +0300, Dmitry Kasatkin wrote: >> > > 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 >> > >> > Right, that should be 'else if'. >> > >> > > 2. It prevents adding trusted keys to ".ima" from user space... >> > > This is NOT what we want... right? >> > >> > It prevents creating a dot prefixed keyring. >> > >> >> May be. But it prevents also adding the key.... >> It needs to distinguish key adding and keyring adding then... > > Perhaps, but assuming you created a keyring on @u, you would still need > to look up the keyid and use it. The same is true here. Instead of > using "keyctl search @u keyring _ima", you would use "keyctl describe % > keyring:.ima". The first field is the keyring id. > > Mimi >
Not perhaps, but for sure. In the case of adding the key, "description" is not a keyring name... it is a key name. In the case of adding keyring, "description" is a keyring name... - Dmitry -- 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/