From patchwork Thu Dec 5 11:41:51 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: 13895088 X-Patchwork-Delegate: snitzer@redhat.com Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 0AB12207E12 for ; Thu, 5 Dec 2024 11:42:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733398976; cv=none; b=XBpNIvMdL28FJ2DKJyFRzvgyBDzmbCTdgOO3RiOPlHS3aSY4UX/NFlwRyg4UUVAEcp27kV/cmmn9aYVO1p3USfFwaFoAng9FuV0iEpXkxwaPpTorznRJQnFwc5TXnDSd6TT3F3GnVos58YlvM2mjOb+EZF2+5VRhICUiJL0YjXw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733398976; c=relaxed/simple; bh=xHuJ2Z2bSmCo0Hm1iTg1LQEKiRWGqlQk4PzkWmtuxYs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:content-type; b=oWKlb4iqpsk/rzkP/d0ZBmUWabW6+n6Aopow3bwKm+6p4zxnBRw1/zYCeNfyGT2ihLF94TyoOrlHmOFaAPChycSITcM1ZyOMuaLAVyWUUGEUfm2wE/8e0OvmnEVIE3WiYnqt0Ati232Ak+5SBl9ZVwgFPQX69qP3s9/JA8AtAds= 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=X06cNDfC; arc=none smtp.client-ip=170.10.129.124 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="X06cNDfC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1733398974; 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=Te8ZvVw+O5gq4halpcCzze57tU3DuBnleFTWqguRczw=; b=X06cNDfCoZZQtLrEwV8KnK6LlK6k6n0n4oB+MGAnOUIMhi7cP+y7SnBhC7S0ZQK/hI45lW j15eOWuJB+zMa0WA3J5sIkx4QmGmEZIG2h7WLsAqDNvmyemAy3k4HCCC7td+lHVheYnmgc yTRa1IUEcFuD9bSU67IIAD2eRXaB3DA= 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-427-2nmQ7ydEO_61CuwQZFidyQ-1; Thu, 05 Dec 2024 06:42:22 -0500 X-MC-Unique: 2nmQ7ydEO_61CuwQZFidyQ-1 X-Mimecast-MFC-AGG-ID: 2nmQ7ydEO_61CuwQZFidyQ Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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 987F91955F43; Thu, 5 Dec 2024 11:42:21 +0000 (UTC) Received: from thinkpad.redhat.com (unknown [10.67.24.108]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4607D1956094; Thu, 5 Dec 2024 11:42:17 +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 v2 1/3] dm array: fix releasing a faulty array block twice in dm_array_cursor_end Date: Thu, 5 Dec 2024 19:41:51 +0800 Message-ID: <20241205114153.1496986-2-mtsai@redhat.com> In-Reply-To: <20241205114153.1496986-1-mtsai@redhat.com> References: <20241205114153.1496986-1-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 10.30.177.15 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: H3am9WRaS2APCSc0CKDjl41BRYhyDads6rYky7Ct31g_1733398941 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 | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/md/persistent-data/dm-array.c b/drivers/md/persistent-data/dm-array.c index 157c9bd2fed7..4866ff56125f 100644 --- a/drivers/md/persistent-data/dm-array.c +++ b/drivers/md/persistent-data/dm-array.c @@ -917,23 +917,27 @@ 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: + dm_btree_cursor_end(&c->cursor); + c->block = NULL; + c->ab = NULL; return r; }