From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93F57749A for ; Thu, 12 Jan 2023 14:05:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13C9BC433EF; Thu, 12 Jan 2023 14:05:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673532342; bh=pwChACz15408BrxxBbVySZ6FjhFLXRJpakzaCXuuH9k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w7xb7wlfO9L4hd436vku0pNOfJiAzA12cjoa140KdMbAt9tZQMObGm7ef4ILNFY4y wZHSjimBsSU1ERMptC5ZH2lznIL4gAEQOI89jkPKy3dAp7zD8nlXFrJbsZ+emZd39H OGgOmS2+DwCSyD5HTbNtHnGbh3QNjq9HaCBLyhJ0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, GUO Zihua , Roberto Sassu , Mimi Zohar , Sasha Levin Subject: [PATCH 5.10 130/783] ima: Handle -ESTALE returned by ima_filter_rule_match() Date: Thu, 12 Jan 2023 14:47:26 +0100 Message-Id: <20230112135530.332393957@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230112135524.143670746@linuxfoundation.org> References: <20230112135524.143670746@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: GUO Zihua [ Upstream commit c7423dbdbc9ecef7fff5239d144cad4b9887f4de ] IMA relies on the blocking LSM policy notifier callback to update the LSM based IMA policy rules. When SELinux update its policies, IMA would be notified and starts updating all its lsm rules one-by-one. During this time, -ESTALE would be returned by ima_filter_rule_match() if it is called with a LSM rule that has not yet been updated. In ima_match_rules(), -ESTALE is not handled, and the LSM rule is considered a match, causing extra files to be measured by IMA. Fix it by re-initializing a temporary rule if -ESTALE is returned by ima_filter_rule_match(). The origin rule in the rule list would be updated by the LSM policy notifier callback. Fixes: b16942455193 ("ima: use the lsm policy update notifier") Signed-off-by: GUO Zihua Reviewed-by: Roberto Sassu Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin --- security/integrity/ima/ima_policy.c | 41 ++++++++++++++++++++++------- 1 file changed, 32 insertions(+), 9 deletions(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 4c937ff2e4dd..a83ce111cf50 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -503,6 +503,9 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, const char *keyring) { int i; + bool result = false; + struct ima_rule_entry *lsm_rule = rule; + bool rule_reinitialized = false; if (func == KEY_CHECK) { return (rule->flags & IMA_FUNC) && (rule->func == func) && @@ -545,35 +548,55 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, int rc = 0; u32 osid; - if (!rule->lsm[i].rule) { - if (!rule->lsm[i].args_p) + if (!lsm_rule->lsm[i].rule) { + if (!lsm_rule->lsm[i].args_p) continue; else return false; } + +retry: switch (i) { case LSM_OBJ_USER: case LSM_OBJ_ROLE: case LSM_OBJ_TYPE: security_inode_getsecid(inode, &osid); - rc = ima_filter_rule_match(osid, rule->lsm[i].type, + rc = ima_filter_rule_match(osid, lsm_rule->lsm[i].type, Audit_equal, - rule->lsm[i].rule); + lsm_rule->lsm[i].rule); break; case LSM_SUBJ_USER: case LSM_SUBJ_ROLE: case LSM_SUBJ_TYPE: - rc = ima_filter_rule_match(secid, rule->lsm[i].type, + rc = ima_filter_rule_match(secid, lsm_rule->lsm[i].type, Audit_equal, - rule->lsm[i].rule); + lsm_rule->lsm[i].rule); break; default: break; } - if (!rc) - return false; + + if (rc == -ESTALE && !rule_reinitialized) { + lsm_rule = ima_lsm_copy_rule(rule); + if (lsm_rule) { + rule_reinitialized = true; + goto retry; + } + } + if (!rc) { + result = false; + goto out; + } } - return true; + result = true; + +out: + if (rule_reinitialized) { + for (i = 0; i < MAX_LSM_RULES; i++) + ima_filter_rule_free(lsm_rule->lsm[i].rule); + kfree(lsm_rule); + } + return result; } /* -- 2.35.1