From patchwork Tue Oct 22 07:12:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming-Hung Tsai X-Patchwork-Id: 13845227 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 79504811EB for ; Tue, 22 Oct 2024 07:13:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729581203; cv=none; b=eERh+XSUWMChb9t8T1q23bF6NylaZSLLvQon5F5CZwtHEIH4ElhDcy14E0UEJFBX8FAb5bJCbr73CYfulFIsleOag1VZJsWEkAvDkw9+8EoYZh3BeKMxziSBFgTJGYeW/amXnLKWfQq9km30wx8uTJFb+8cSg5F9i9B/M2rE1wU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729581203; c=relaxed/simple; bh=unU4UT6uHhuCMbnR3FDf75CJxVt9vCvUoOXnUuj6lYs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=pCYCOKRuzUXv4IDGonnihpbb6Xy1SrCaGKzP3O+Z1B9RbVUg9ZLJvxk0CuNAFiM9cPJDvLCPalMtVoLo85S7dF5hzRNQ2IfRJcJSFJ42C12ESVEkMLBzPXhhdBgzKEtwnbyUFp0dLBTilcj7SV9malyhBKh6eexIWIjQxdE6Zi0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=NtPCR6Lf; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NtPCR6Lf" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1729581200; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=IVpuDtQU3pAVsys2rDmJn13j/4rUMXRgZrmwgtPiep8=; b=NtPCR6LfWOYy7POA5UOUo/Wwrsl4wl+JB0Tki4swP8R4fe2rBZp2nbzgArLpQqCEjLH0w5 cKl1li5VfgVWcMtroJrJP6tpZB4MDbx5uyDq8IkmI1sibYgLRmLgOFIS9y/4H7Nzl+Sdri nhz1AYridmqEGsuOpnpXPAcJ1Uzjsng= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-288-ZIiRLEW3Oo6I02T16cFZ9g-1; Tue, 22 Oct 2024 03:13:17 -0400 X-MC-Unique: ZIiRLEW3Oo6I02T16cFZ9g-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2FE331956089; Tue, 22 Oct 2024 07:13:16 +0000 (UTC) Received: from thinkpad.redhat.com (unknown [10.67.24.92]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 29C4319560B2; Tue, 22 Oct 2024 07:13:11 +0000 (UTC) From: Ming-Hung Tsai To: dm-devel@lists.linux.dev Cc: mpatocka@redhat.com, thornber@redhat.com, heinzm@redhat.com, snitzer@kernel.org, luomeng12@huawei.com, Ming-Hung Tsai Subject: [PATCH 2/5] dm cache: fix flushing uninitialized delayed_work on cache_ctr error Date: Tue, 22 Oct 2024 15:12:49 +0800 Message-ID: <20241022071249.778584-1-mtsai@redhat.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com An unexpected WARN_ON from flush_work() may occur when cache creation fails, caused by destroying the uninitialized delayed_work waker in the error path of cache_create(). For example, the warning appears on the superblock checksum error. Reproduce steps: dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 65536 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/urandom of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" Kernel logs: (snip) WARNING: CPU: 0 PID: 84 at kernel/workqueue.c:4178 __flush_work+0x5d4/0x890 Fix by pulling out the cancel_delayed_work_sync() from the constructor's error path. This patch doesn't affect the use-after-free fix for concurrent dm_resume and dm_destroy (commit 6a459d8edbdb ("dm cache: Fix UAF in destroy()")) as cache_dtr is not changed. Signed-off-by: Ming-Hung Tsai Fixes: 6a459d8edbdb ("dm cache: Fix UAF in destroy()") --- drivers/md/dm-cache-target.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 90772b42c234..68e9a1abd303 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -1905,16 +1905,13 @@ static void check_migrations(struct work_struct *ws) * This function gets called on the error paths of the constructor, so we * have to cope with a partially initialised struct. */ -static void destroy(struct cache *cache) +static void __destroy(struct cache *cache) { - unsigned int i; - mempool_exit(&cache->migration_pool); if (cache->prison) dm_bio_prison_destroy_v2(cache->prison); - cancel_delayed_work_sync(&cache->waker); if (cache->wq) destroy_workqueue(cache->wq); @@ -1942,13 +1939,22 @@ static void destroy(struct cache *cache) if (cache->policy) dm_cache_policy_destroy(cache->policy); + bioset_exit(&cache->bs); + + kfree(cache); +} + +static void destroy(struct cache *cache) +{ + unsigned int i; + + cancel_delayed_work_sync(&cache->waker); + for (i = 0; i < cache->nr_ctr_args ; i++) kfree(cache->ctr_args[i]); kfree(cache->ctr_args); - bioset_exit(&cache->bs); - - kfree(cache); + __destroy(cache); } static void cache_dtr(struct dm_target *ti) @@ -2561,7 +2567,7 @@ static int cache_create(struct cache_args *ca, struct cache **result) *result = cache; return 0; bad: - destroy(cache); + __destroy(cache); return r; } @@ -2612,7 +2618,7 @@ static int cache_ctr(struct dm_target *ti, unsigned int argc, char **argv) r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3); if (r) { - destroy(cache); + __destroy(cache); goto out; }