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 X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53C74C46475 for ; Thu, 25 Oct 2018 14:17:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1CE920840 for ; Thu, 25 Oct 2018 14:17:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="A0iHyx3G" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F1CE920840 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729618AbeJYWuW (ORCPT ); Thu, 25 Oct 2018 18:50:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:59704 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729604AbeJYWuV (ORCPT ); Thu, 25 Oct 2018 18:50:21 -0400 Received: from sasha-vm.mshome.net (unknown [167.98.65.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1325020868; Thu, 25 Oct 2018 14:17:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540477044; bh=GlgbpS+Mil5Q++YFFNntIzJXVwpG9kmImRs665ah7b8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A0iHyx3GBIhigIwCUB46AhgEjBItbkY8KI7UVnfItAO3TvfOkbZksKmL1SBtYxrPW It6A4uAfct34hO4xd6tYoeIbhJn2P0Ui6nbt9kJ7YFyWziWGvIsBLGawgb7dQ8VjzL qoO0jigyknUME4xdq8RzzhATiVqQ7xVqRE3mmmXw= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andrey Ryabinin , Matthew Wilcox , Hugh Dickins , Ross Zwisler , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 4.4 09/65] radix-tree: fix radix_tree_iter_retry() for tagged iterators. Date: Thu, 25 Oct 2018 10:16:09 -0400 Message-Id: <20181025141705.213937-9-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181025141705.213937-1-sashal@kernel.org> References: <20181025141705.213937-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrey Ryabinin [ Upstream commit 3cb9185c67304b2a7ea9be73e7d13df6fb2793a1 ] radix_tree_iter_retry() resets slot to NULL, but it doesn't reset tags. Then NULL slot and non-zero iter.tags passed to radix_tree_next_slot() leading to crash: RIP: radix_tree_next_slot include/linux/radix-tree.h:473 find_get_pages_tag+0x334/0x930 mm/filemap.c:1452 .... Call Trace: pagevec_lookup_tag+0x3a/0x80 mm/swap.c:960 mpage_prepare_extent_to_map+0x321/0xa90 fs/ext4/inode.c:2516 ext4_writepages+0x10be/0x2b20 fs/ext4/inode.c:2736 do_writepages+0x97/0x100 mm/page-writeback.c:2364 __filemap_fdatawrite_range+0x248/0x2e0 mm/filemap.c:300 filemap_write_and_wait_range+0x121/0x1b0 mm/filemap.c:490 ext4_sync_file+0x34d/0xdb0 fs/ext4/fsync.c:115 vfs_fsync_range+0x10a/0x250 fs/sync.c:195 vfs_fsync fs/sync.c:209 do_fsync+0x42/0x70 fs/sync.c:219 SYSC_fdatasync fs/sync.c:232 SyS_fdatasync+0x19/0x20 fs/sync.c:230 entry_SYSCALL_64_fastpath+0x23/0xc1 arch/x86/entry/entry_64.S:207 We must reset iterator's tags to bail out from radix_tree_next_slot() and go to the slow-path in radix_tree_next_chunk(). Fixes: 46437f9a554f ("radix-tree: fix race in gang lookup") Link: http://lkml.kernel.org/r/1468495196-10604-1-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin Reported-by: Dmitry Vyukov Acked-by: Konstantin Khlebnikov Cc: Matthew Wilcox Cc: Hugh Dickins Cc: Ross Zwisler Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/linux/radix-tree.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 5d5174b59802..673dee29a9b9 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -382,6 +382,7 @@ static inline __must_check void **radix_tree_iter_retry(struct radix_tree_iter *iter) { iter->next_index = iter->index; + iter->tags = 0; return NULL; } -- 2.17.1