From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Dmitry Kasatkin" , "Mimi Zohar" , "David Howells" Date: Thu, 01 Jun 2017 16:40:55 +0100 Message-ID: Subject: [PATCH 3.2 070/101] KEYS: special dot prefixed keyring name bug fix In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2.89-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mimi Zohar commit a4e3b8d79a5c6d40f4a9703abf7fe3abcc6c3b8d upstream. 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(). Changelog v6: - whitespace and other cleanup Changelog v5: - Only prevent userspace from creating a dot prefixed keyring, not regular keys - Dmitry Reported-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar Acked-by: David Howells [bwh: Backported to 3.2: adjust context, indentation] Signed-off-by: Ben Hutchings --- security/keys/keyctl.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -35,8 +35,6 @@ static int key_get_type_from_user(char * return ret; if (ret == 0 || ret >= len) return -EINVAL; - if (type[0] == '.') - return -EPERM; type[len - 1] = '\0'; return 0; } @@ -75,6 +73,10 @@ SYSCALL_DEFINE5(add_key, const char __us if (IS_ERR(description)) { ret = PTR_ERR(description); goto error; + } else if ((description[0] == '.') && + (strncmp(type, "keyring", 7) == 0)) { + ret = -EPERM; + goto error2; } /* pull the payload in if one was supplied */