[RFC PATCH v4 1/4] KEYS: special dot prefixed keyring name bug fix

From: Mimi Zohar
Date: Wed May 28 2014 - 11:10:08 EST


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.kasatkin@xxxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
---
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;
+ }
}

/* pull the payload in if one was supplied */
--
1.8.1.4

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