From patchwork Wed Jan 5 14:36:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 12705504 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7CCDC4332F for ; Thu, 6 Jan 2022 15:45:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240643AbiAFPpt (ORCPT ); Thu, 6 Jan 2022 10:45:49 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:50276 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240584AbiAFPpq (ORCPT ); Thu, 6 Jan 2022 10:45:46 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 513652112A; Thu, 6 Jan 2022 15:45:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1641483945; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XI20t3x6VluxG/lEe3pVn9R5bOW+Q1xeNYKAadDibN0=; b=2aMcAwOjv3tN6KVz42xVTCTqcXhUCB3J2tn+LXeQeCMmTq8M2AeOl5ajzhLiA+zDsSkmHO 2DQm88d+Vfxfudju2pWYyEvkpTWhAVCj5xS9d8x62dyAA85LpcnMiAYZ4XHvHHCEylRfvU XGfTKecPhpYBiEaOd453ZvdlXEToxnU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1641483945; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XI20t3x6VluxG/lEe3pVn9R5bOW+Q1xeNYKAadDibN0=; b=8YFk5AtUz/abnPVcy9O2O4XZwWFnUsqSJo3h0aTB3Hb9jh5AvnDwKicEDk1ie5hd49XaKo fpbPwZrItw+tpcBg== Received: from quack3.suse.cz (unknown [10.163.43.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 4594EA3B89; Thu, 6 Jan 2022 15:45:45 +0000 (UTC) Received: by localhost (Postfix, from userid 1000) id D8BC4A084C; Wed, 5 Jan 2022 15:36:39 +0100 (CET) From: Jan Kara To: Cc: Paolo Valente , Jens Axboe , "yukuai (C)" , Jan Kara , stable@vger.kernel.org Subject: [PATCH 5/5] bfq: Update cgroup information before merging bio Date: Wed, 5 Jan 2022 15:36:36 +0100 Message-Id: <20220105143639.31266-5-jack@suse.cz> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220105143037.20542-1-jack@suse.cz> References: <20220105143037.20542-1-jack@suse.cz> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1410; h=from:subject; bh=C0+SJ39G5KroczINGXi/DmV/R4t2VczWioMIeh5rfLk=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBh1az0bT4FhjQ/C3K9EvbFmFE27QKGZ0RF44hR8KVz AKfB/uOJATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCYdWs9AAKCRCcnaoHP2RA2d3gCA CxEIICfQmj0qLCyG49URS9AtsNC7S/UKlG6HzbDjzE16TxVcY0OTuJXEnk7SPqykvMpZ/BkwIjrECJ GaIGUeUruWbMRUfKhiqc3+dyh5sMC8OSqMd9X35stuFg4AiKjWLYDV89dPuwexJP0/whI4/3H8uLD5 o7Z869Qtp8j2KcD7hAH0Bdr1yosJtd2iGosPpMWelDujKFe99LIJWEMPtjKYV/cC68wOjWctAftFIb yuaio53FKWNLXY6BX4oMduVH2PtC9e95UjQczrtyTu6CB0JNuYkEqtV7Hd5Y+ShYJVtTzj3jcqaFH3 MVuRAAMqy7Q4cwDAcXvjbFfhS6alNG X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org When the process is migrated to a different cgroup (or in case of writeback just starts submitting bios associated with a different cgroup) bfq_merge_bio() can operate with stale cgroup information in bic. Thus the bio can be merged to a request from a different cgroup or it can result in merging of bfqqs for different cgroups or bfqqs of already dead cgroups and causing possible use-after-free issues. Fix the problem by updating cgroup information in bfq_merge_bio(). CC: stable@vger.kernel.org Fixes: e21b7a0b9887 ("block, bfq: add full hierarchical scheduling and cgroups support") Signed-off-by: Jan Kara --- block/bfq-iosched.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 654191c6face..f77f79d1d04c 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2337,10 +2337,17 @@ static bool bfq_bio_merge(struct request_queue *q, struct bio *bio, spin_lock_irq(&bfqd->lock); - if (bic) + if (bic) { + /* + * Make sure cgroup info is uptodate for current process before + * considering the merge. + */ + bfq_bic_update_cgroup(bic, bio); + bfqd->bio_bfqq = bic_to_bfqq(bic, op_is_sync(bio->bi_opf)); - else + } else { bfqd->bio_bfqq = NULL; + } bfqd->bio_bic = bic; ret = blk_mq_sched_try_merge(q, bio, nr_segs, &free);