From patchwork Tue Dec 3 17:38:49 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: 13892767 X-Patchwork-Delegate: snitzer@redhat.com 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 747B91F8AD2 for ; Tue, 3 Dec 2024 17:39:06 +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=1733247548; cv=none; b=LxSOYmnssBuoz18iEErEUzFA62Xz9cKsLwqLB6EyhYP/wWzU661ZFrTuKvG60nxFtrEgIV3j8QOkMGguIHmpCsmTJ6hC4G06LX7+KNhM8OCPgQE/v8Z5TwjdfTnMQE3wxXQeN1m6CczMoN8+NITxqIM03s02lQ7hk68SdXWpH98= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733247548; c=relaxed/simple; bh=cnf4vNSINpKH8eXM2kpr7r2gin3qLFoBtzgS2hpkGoM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:content-type; b=FwRIWB5UIzsT5xrXIEzfmTuv8sQdSYzP82xgPFbCp2MjokQiWOkyjFInybKJe5KZJLEPW143PgM4pv7PppHFHNifoz6YEJZLW6dysXuHazlIDULr2xgucJ7EJOtVszq8EK/0JsPOOxbXKVNkNB129y/veHKJJt+NGlM78YlFqEk= 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=RyXY6swt; 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="RyXY6swt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1733247545; 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: in-reply-to:in-reply-to:references:references; bh=PVZwHTojO+ZL0SimvTlVGTrW6hfMS7wtkNK0d6n7hvg=; b=RyXY6swtMckJQiH7mYjQSWiTt0aRT7DElZmqs4ikk+MRuMxmp2xyrRrtKk53k8sk1Kd1nP XhAbmn9IFg1pDBLaLejHF1pioAASysRvGrjyyt8YwW1fmvaxzdo+SUXGf6d/TlDWr6Yevv loYRnfFqvmdT23eiadXbBRfjag53SVw= Received: from mx-prod-mc-04.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-622-8Mn_iC-qOVac0haezrmTpQ-1; Tue, 03 Dec 2024 12:39:03 -0500 X-MC-Unique: 8Mn_iC-qOVac0haezrmTpQ-1 X-Mimecast-MFC-AGG-ID: 8Mn_iC-qOVac0haezrmTpQ Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0988619560A2; Tue, 3 Dec 2024 17:39:03 +0000 (UTC) Received: from thinkpad.redhat.com (unknown [10.67.24.41]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 708671956054; Tue, 3 Dec 2024 17:38:59 +0000 (UTC) From: Ming-Hung Tsai To: dm-devel@lists.linux.dev Cc: Mikulas Patocka , Joe Thornber , Heinz Mauelshagen , Mike Snitzer , Ming-Hung Tsai Subject: [PATCH 1/3] dm array: fix releasing a faulty array block twice in dm_array_cursor_end Date: Wed, 4 Dec 2024 01:38:49 +0800 Message-ID: <20241203173849.1258066-1-mtsai@redhat.com> In-Reply-To: <20241203173658.1257887-1-mtsai@redhat.com> References: <20241203173658.1257887-1-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 10.30.177.40 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 5qACcumsKOxSc5ke4nrZUJ89Orpb_SSCpmfW433WVPc_1733247543 X-Mimecast-Originator: redhat.com content-type: text/plain; charset="US-ASCII"; x-default=true When dm_bm_read_lock() fails due to locking or checksum errors, it releases the faulty block implicitly while leaving an invalid output pointer behind. The caller of dm_bm_read_lock() should not operate on this invalid dm_block pointer, or it will lead to undefined result. For example, the dm_array_cursor incorrectly caches the invalid pointer on reading a faulty array block, causing a double release in dm_array_cursor_end(), then hitting the BUG_ON in dm-bufio cache_put(). Reproduce steps: 1. initialize a cache device 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 $262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" 2. wipe the second array block offline dmsteup remove cache cmeta cdata corig mapping_root=$(dd if=/dev/sdc bs=1c count=8 skip=192 \ 2>/dev/null | hexdump -e '1/8 "%u\n"') ablock=$(dd if=/dev/sdc bs=1c count=8 skip=$((4096*mapping_root+2056)) \ 2>/dev/null | hexdump -e '1/8 "%u\n"') dd if=/dev/zero of=/dev/sdc bs=4k count=1 seek=$ablock 3. try reopen the cache device 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" 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) device-mapper: array: array_block_check failed: blocknr 0 != wanted 10 device-mapper: block manager: array validator check failed for block 10 device-mapper: array: get_ablock failed device-mapper: cache metadata: dm_array_cursor_next for mapping failed ------------[ cut here ]------------ kernel BUG at drivers/md/dm-bufio.c:638! Fix by setting the cached block pointer to NULL on errors. Signed-off-by: Ming-Hung Tsai Fixes: fdd1315aa5f0 ("dm array: introduce cursor api") --- drivers/md/persistent-data/dm-array.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/md/persistent-data/dm-array.c b/drivers/md/persistent-data/dm-array.c index 157c9bd2fed7..c46a374f7459 100644 --- a/drivers/md/persistent-data/dm-array.c +++ b/drivers/md/persistent-data/dm-array.c @@ -917,23 +917,28 @@ static int load_ablock(struct dm_array_cursor *c) if (c->block) unlock_ablock(c->info, c->block); - c->block = NULL; - c->ab = NULL; c->index = 0; r = dm_btree_cursor_get_value(&c->cursor, &key, &value_le); if (r) { DMERR("dm_btree_cursor_get_value failed"); dm_btree_cursor_end(&c->cursor); + goto out; } else { r = get_ablock(c->info, le64_to_cpu(value_le), &c->block, &c->ab); if (r) { DMERR("get_ablock failed"); dm_btree_cursor_end(&c->cursor); + goto out; } } + return 0; + +out: + c->block = NULL; + c->ab = NULL; return r; }