From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1C0FC43381 for ; Fri, 22 Mar 2019 12:46:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACC56218E2 for ; Fri, 22 Mar 2019 12:46:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553258766; bh=pO7Pgz5Fam1Sals91NQwuGLMS7g+6QQSgUSgPtqwR+c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GKhhLDWegBiW+WuIZOlJ/Y2sL/tsutNz285E20ydnvmjlUXeITpitZpuJo4IS58DV jFFiYAX7c6adupohX5vGDbeVHZRDpZaeRaZbcHdrue47sDy2OrtMTVd+KtBWMt5V0T u3kXJnSKpgIZ+eVJTQtYydjvFFQrjC2xAy15MW+E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730503AbfCVMqF (ORCPT ); Fri, 22 Mar 2019 08:46:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:36908 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387473AbfCVL7w (ORCPT ); Fri, 22 Mar 2019 07:59:52 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 167892192D; Fri, 22 Mar 2019 11:59:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553255991; bh=pO7Pgz5Fam1Sals91NQwuGLMS7g+6QQSgUSgPtqwR+c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w0kxuivHgtS8XgwvfuyrXghs7Ew8YWOKkk1V5Uw/GvWPYGVfgjIXYNmzXokcAta1X ba4Qr3Ro3UKYnpFlVus3m35CiWdugZOY1BAI2KBDwfH0tQ62s5ZjssfYU01U7ckzJ0 W16FXQhuN+qHvY2ygAjHF7l+JsvKaIskCpmBdLJs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Howells , James Morris , Sasha Levin Subject: [PATCH 4.19 076/280] assoc_array: Fix shortcut creation Date: Fri, 22 Mar 2019 12:13:49 +0100 Message-Id: <20190322111310.620431889@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111306.356185024@linuxfoundation.org> References: <20190322111306.356185024@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit bb2ba2d75a2d673e76ddaf13a9bd30d6a8b1bb08 ] Fix the creation of shortcuts for which the length of the index key value is an exact multiple of the machine word size. The problem is that the code that blanks off the unused bits of the shortcut value malfunctions if the number of bits in the last word equals machine word size. This is due to the "<<" operator being given a shift of zero in this case, and so the mask that should be all zeros is all ones instead. This causes the subsequent masking operation to clear everything rather than clearing nothing. Ordinarily, the presence of the hash at the beginning of the tree index key makes the issue very hard to test for, but in this case, it was encountered due to a development mistake that caused the hash output to be either 0 (keyring) or 1 (non-keyring) only. This made it susceptible to the keyctl/unlink/valid test in the keyutils package. The fix is simply to skip the blanking if the shift would be 0. For example, an index key that is 64 bits long would produce a 0 shift and thus a 'blank' of all 1s. This would then be inverted and AND'd onto the index_key, incorrectly clearing the entire last word. Fixes: 3cb989501c26 ("Add a generic associative array implementation.") Signed-off-by: David Howells Signed-off-by: James Morris Signed-off-by: Sasha Levin --- lib/assoc_array.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/lib/assoc_array.c b/lib/assoc_array.c index c6659cb37033..59875eb278ea 100644 --- a/lib/assoc_array.c +++ b/lib/assoc_array.c @@ -768,9 +768,11 @@ all_leaves_cluster_together: new_s0->index_key[i] = ops->get_key_chunk(index_key, i * ASSOC_ARRAY_KEY_CHUNK_SIZE); - blank = ULONG_MAX << (level & ASSOC_ARRAY_KEY_CHUNK_MASK); - pr_devel("blank off [%zu] %d: %lx\n", keylen - 1, level, blank); - new_s0->index_key[keylen - 1] &= ~blank; + if (level & ASSOC_ARRAY_KEY_CHUNK_MASK) { + blank = ULONG_MAX << (level & ASSOC_ARRAY_KEY_CHUNK_MASK); + pr_devel("blank off [%zu] %d: %lx\n", keylen - 1, level, blank); + new_s0->index_key[keylen - 1] &= ~blank; + } /* This now reduces to a node splitting exercise for which we'll need * to regenerate the disparity table. -- 2.19.1