From patchwork Wed Mar 30 12:42:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 12795779 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 6A413C433EF for ; Wed, 30 Mar 2022 12:45:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345728AbiC3MrI (ORCPT ); Wed, 30 Mar 2022 08:47:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345236AbiC3Mqy (ORCPT ); Wed, 30 Mar 2022 08:46:54 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 97D5B7DE16; Wed, 30 Mar 2022 05:43:02 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 2E0C81F7AB; Wed, 30 Mar 2022 12:43:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1648644181; 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=RQpb3DlBpC+xUzJx/SvzpuHxoRpxIiDopbRVeNdSa9A=; b=yR5UWcrbn14XpWeWjX5H6HlNocJ16DztxIg7aPmwVLIq4VH4hY5gO9mr+pDHF0/5LMEHRL cVpcZ+6oRrfvj1fDHaousDrG2RYQApIkSIuzKkXefILHzX3xAn/teQuVYj/+j7J5YBcPzj +0qsftB9lTnGKin+iMojNJI6W5sXIM8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1648644181; 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=RQpb3DlBpC+xUzJx/SvzpuHxoRpxIiDopbRVeNdSa9A=; b=u6cKgGrGYXHqcfeLJb6mXH76Bf9vSh3/Z8nXsWCZIL3zBbP7NxAp/j/jUOehB6ZQ/Fe0hL Ak22qhc53arabJBA== Received: from quack3.suse.cz (unknown [10.163.28.18]) (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 19BA9A3B83; Wed, 30 Mar 2022 12:43:01 +0000 (UTC) Received: by quack3.suse.cz (Postfix, from userid 1000) id 78D4CA061A; Wed, 30 Mar 2022 14:42:56 +0200 (CEST) From: Jan Kara To: Cc: Paolo Valente , Jens Axboe , "yukuai (C)" , Jan Kara , stable@vger.kernel.org Subject: [PATCH 4/9] bfq: Update cgroup information before merging bio Date: Wed, 30 Mar 2022 14:42:47 +0200 Message-Id: <20220330124255.24581-4-jack@suse.cz> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220330123438.32719-1-jack@suse.cz> References: <20220330123438.32719-1-jack@suse.cz> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1409; h=from:subject; bh=vBnlnDsUwY71kZB9dCskeOZQL4WP3DTzp9qFZwDR62M=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBiRFBH7s2MVgHfYyX7/j3Uz+L7Pwc2kwt7cjXogDoj nSmTnGWJATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCYkRQRwAKCRCcnaoHP2RA2RSSB/ 0WB0b7X01Qo+1rx9nKW/zefbr92awfYlpwrSL8lo6045feevYqyavolAM8ZOa9k3I7GtKLYVHzYigp fYZuQrmyUn3ur6/sz58I126oHSGGjaAv902P4tt2JiDr7PN205xZ2AwEIebyJi9Q4gGoxJ+cE74ZcY PvqEBu5aNbHwug8UQxlxV4ZZnmvxOpdt0/3yJohDd7Jldyy4ze5rsj3mi5AvHllz9mWIsxw+cSwr/q joayjRM0nZU0KdoKgE4RU5qdIx3ZO82m6yWi7eZZxumNosImKmgoNv0ZsnFob9JRrSMlGB0hrui5uK FbalNNj69MP8f48mePNHAPO0NsLydj 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 89fe3f85eb3c..1fc4d4628fba 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2457,10 +2457,17 @@ 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);