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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59F89C433FE for ; Fri, 1 Apr 2022 10:28:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245540AbiDAK3p (ORCPT ); Fri, 1 Apr 2022 06:29:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241970AbiDAK3o (ORCPT ); Fri, 1 Apr 2022 06:29:44 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5EDB626E566; Fri, 1 Apr 2022 03:27:55 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id C61CA210FC; Fri, 1 Apr 2022 10:27:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1648808873; 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=9kz4yzWuKqKHnpGX5HVClU1VX8JDHF41CaOQeK0bFmM=; b=vase2uVkwsTdL52H0RMuKpv3tNlREid2a/5wuH5ZsF4NY6DXwfXPvlw2kCcqAAuuAjNyPw Q6ATyXdyqbPVqewJZ3rgH/RuLLlQIqzs9mp6O/KjC23ilHT+W4VleJlP7ZhKvWWQt1bP+c 34uDXm4jYXG5tagz4zKhr11tuWz+kLY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1648808873; 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=9kz4yzWuKqKHnpGX5HVClU1VX8JDHF41CaOQeK0bFmM=; b=uw9KWn9V+62jXZyHOqvdLFqKI6OfiQZSyeS1FUa3fbLOApKXvmRfDy/nKeaSJb44VWjmCK UFZlciojuI+gi4BA== 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 A4107A3B88; Fri, 1 Apr 2022 10:27:53 +0000 (UTC) Received: by quack3.suse.cz (Postfix, from userid 1000) id 875CCA061A; Fri, 1 Apr 2022 12:27:52 +0200 (CEST) From: Jan Kara To: Paolo Valente Cc: , Jens Axboe , "yukuai (C)" , Jan Kara , stable@vger.kernel.org Subject: [PATCH 4/9] bfq: Update cgroup information before merging bio Date: Fri, 1 Apr 2022 12:27:45 +0200 Message-Id: <20220401102752.8599-4-jack@suse.cz> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220401102325.17617-1-jack@suse.cz> References: <20220401102325.17617-1-jack@suse.cz> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1455; h=from:subject; bh=ZXtMvPdme+98TvEer4Fc63SIc5w+HQccSDUrivn0Ttw=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBiRtOhxr8HA9TU7R2le3a3GLod00df5u+vOKGbBIwA +UOFXbeJATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCYkbToQAKCRCcnaoHP2RA2UA1B/ 4s/xVxYae2jfiby2vEr7yP16xSSAlPNPznE2wAYZdRP1HZsmwXMabpNPa+8rZMMQDNTHcnoULZ7EEh r3xB/PO/vsYCyGUzaB8sIBjaSxFFo3HwjZ+grmYicnY5q7oudywN7LTHlRvkYizRwg25jA2UB4Ascn U5kggrSnQVvPHrRsQQcrtPAGrij8xc0rl285Vf0PRJromv5ls2BtscqpNkF+DZc0KbchCLC/bvCfVb y6o/K1+P8b6fiyIEiLRrGYgyMa0vJWVsjDZSPWAENekVVd4/3XV9juuDmwr5E2ULFl9Q39hiwCbQhS mZL+KVGEXsLOG50KdQQHI2TfBoodDU X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Content-Transfer-Encoding: 8bit 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") Tested-by: "yukuai (C)" 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); -- 2.34.1