From patchwork Mon Sep 26 14:20:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Yu X-Patchwork-Id: 12988758 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D893DC32771 for ; Mon, 26 Sep 2022 14:21:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6169A8E005C; Mon, 26 Sep 2022 10:21:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 59F928E0047; Mon, 26 Sep 2022 10:21:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 419E78E005C; Mon, 26 Sep 2022 10:21:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 2AF408E0047 for ; Mon, 26 Sep 2022 10:21:34 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id E00E6A52F6 for ; Mon, 26 Sep 2022 14:21:33 +0000 (UTC) X-FDA: 79954449666.28.1DDB99A Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf11.hostedemail.com (Postfix) with ESMTP id 751B440009 for ; Mon, 26 Sep 2022 14:21:33 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id C3EF6B8068A; Mon, 26 Sep 2022 14:21:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DEDADC43470; Mon, 26 Sep 2022 14:21:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664202090; bh=h7h74y8er6BoIqIK+NiPbrmtuB0Riz6+hSGGmV7Df14=; h=From:To:Cc:Subject:Date:From; b=lD8hNLrbF6sEGxqr/uldD4SMD1/tmZ91P2U76f5F94M3ttIK7XzG20QvpXfvGj6Jb byAuOwCw9q9DFaUA2ihHJmEs2/Apa+L8oF+kJ6dTBWqTFu+bGFp1k5qkrZ+sofiVDk spp+BQghx/FQTVuBbTO72vfrblLBPZNzUi0pU4cOEX9zCo/9IzhXBeA1Wp8ae3vOr5 RuzUuKqP8PekEgUcpthxxGBqASHtm5bgrdzR8/XerWfAL3+ikq7PKZIuTYSOJvLrhv GyyYv32PeOdsK+KDlCpsn3jgiU5LeuptI2idvQXUTMo3tHASXeHG89xzQOTYqEdEVx /zPc6DTKNUuXg== From: Chao Yu To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Hugh Dickins Cc: chao@kernel.org, Chao Yu , Christophe JAILLET , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] mm/slub: clean up create_unique_id() Date: Mon, 26 Sep 2022 22:20:41 +0800 Message-Id: <20220926142042.2725-1-chao@kernel.org> X-Mailer: git-send-email 2.36.1 MIME-Version: 1.0 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664202093; a=rsa-sha256; cv=none; b=0Rfs/3TUrmSCL+0iepeogfqz/W/FexohQBumi1fKy4rldEVVoNnQon2ZcanYqRYKtKnMti nGjB7cd+grTpuaTEaGW2tT2T4HdAxlG6jR+bNPLdmSFzB+n2nKb25sd+0LuproXwm9AVGY eOKnzl2eEPRgSdnTCVWdlAjcauiYPJ0= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=lD8hNLrb; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf11.hostedemail.com: domain of chao@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=chao@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664202093; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=uoPS5mn4DhmYFRtoWD/dHv+e6nkqvPpeTS5EIpm69ps=; b=ZEAOS9TvQFRZ8HEpAopWZlNcEY7nKKUKufU/1BJcGncOE+pgplPfpq9XQydL6hvdZDPvU+ RJDLG/knouFcdiH5QP0AJXK7101wpTw9mi8sAHRY8f6MtxuQ5+yZMPkB5YuCqb3mFA1FRI GJV1MpDPFD5ASOcQFkO0CPprBjYCSrA= X-Stat-Signature: tjcg13ht1bnqstobe3jujbodi3f38m81 X-Rspam-User: X-Rspamd-Server: rspam04 Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=lD8hNLrb; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf11.hostedemail.com: domain of chao@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=chao@kernel.org X-Rspamd-Queue-Id: 751B440009 X-HE-Tag: 1664202093-234132 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Chao Yu As Christophe JAILLET suggested: In create_unique_id(), "looks that ID_STR_LENGTH could even be reduced to 32 or 16. The 2nd BUG_ON at the end of the function could certainly be just removed as well or remplaced by a: if (p > name + ID_STR_LENGTH - 1) { kfree(name); return -E; } " According to above suggestion, let's do below cleanups: 1. reduce ID_STR_LENGTH to 32, as the buffer size should be enough; 2. use WARN_ON instead of BUG_ON() and return error if check condition is true; 3. use snprintf instead of sprintf to avoid overflow. Link: https://lore.kernel.org/linux-mm/2025305d-16db-abdf-6cd3-1fb93371c2b4@wanadoo.fr/ Fixes: 81819f0fc828 ("SLUB core") Suggested-by: Christophe JAILLET Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Chao Yu --- v3: - clean up codes - fix size parameter of snprintf() mm/slub.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 4b98dff9be8e..4d3ee0924533 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5890,7 +5890,7 @@ static inline struct kset *cache_kset(struct kmem_cache *s) return slab_kset; } -#define ID_STR_LENGTH 64 +#define ID_STR_LENGTH 32 /* Create a unique string id for a slab cache: * @@ -5924,9 +5924,12 @@ static char *create_unique_id(struct kmem_cache *s) *p++ = 'A'; if (p != name + 1) *p++ = '-'; - p += sprintf(p, "%07u", s->size); + p += snprintf(p, ID_STR_LENGTH - (p - name), "%07u", s->size); - BUG_ON(p > name + ID_STR_LENGTH - 1); + if (WARN_ON(p > name + ID_STR_LENGTH - 1)) { + kfree(name); + return ERR_PTR(-EINVAL); + } return name; }