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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 496EBC48BD3 for ; Wed, 26 Jun 2019 03:46:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 235B0205ED for ; Wed, 26 Jun 2019 03:46:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561520806; bh=rofvzWsIBCAeGUFGJxZ/YQEGN7NmaGddgE4JIcTL0q4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PE34NvO+AEUvbOTtxXvB9ct5XDME+RAfqgmsOip8pVpRMFHXZ22AoXJcv2xOAjycR WJEnW5U77qpldLN9O953SrmIocDbs5oOSwTOO8+31XcovAi89VS/ITTgYRu2jerUax Vn1ynFaPg8XdAiL3KQxEkdZogBFMkvDMgDzBweho= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728033AbfFZDqo (ORCPT ); Tue, 25 Jun 2019 23:46:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:58582 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728018AbfFZDqn (ORCPT ); Tue, 25 Jun 2019 23:46:43 -0400 Received: from sasha-vm.mshome.net (mobile-107-77-172-90.mobile.att.net [107.77.172.90]) (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 5872421743; Wed, 26 Jun 2019 03:46:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561520801; bh=rofvzWsIBCAeGUFGJxZ/YQEGN7NmaGddgE4JIcTL0q4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xJzQZaxmG07pT5JEAO832ywIodzzq1KIClRH1XboXgaudkM7RUG6OujZ3wtabHTEI cwf5vnImYygKM0yfg1N8SL08tqZqWHAYOudSGAB8O1vkrssHaawpZaFglTHl4oIo1T QJWe05/pZfDBrkSMY9k4DHBY66szAsuoytKebh/k= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: YueHaibing , Hulk Robot , Geert Uytterhoeven , Axel Lin , Mukesh Ojha , Mark Brown , Sasha Levin , linux-spi@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 2/6] spi: bitbang: Fix NULL pointer dereference in spi_unregister_master Date: Tue, 25 Jun 2019 23:46:33 -0400 Message-Id: <20190626034637.24515-2-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190626034637.24515-1-sashal@kernel.org> References: <20190626034637.24515-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: YueHaibing [ Upstream commit 5caaf29af5ca82d5da8bc1d0ad07d9e664ccf1d8 ] If spi_register_master fails in spi_bitbang_start because device_add failure, We should return the error code other than 0, otherwise calling spi_bitbang_stop may trigger NULL pointer dereference like this: BUG: KASAN: null-ptr-deref in __list_del_entry_valid+0x45/0xd0 Read of size 8 at addr 0000000000000000 by task syz-executor.0/3661 CPU: 0 PID: 3661 Comm: syz-executor.0 Not tainted 5.1.0+ #28 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: dump_stack+0xa9/0x10e ? __list_del_entry_valid+0x45/0xd0 ? __list_del_entry_valid+0x45/0xd0 __kasan_report+0x171/0x18d ? __list_del_entry_valid+0x45/0xd0 kasan_report+0xe/0x20 __list_del_entry_valid+0x45/0xd0 spi_unregister_controller+0x99/0x1b0 spi_lm70llp_attach+0x3ae/0x4b0 [spi_lm70llp] ? 0xffffffffc1128000 ? klist_next+0x131/0x1e0 ? driver_detach+0x40/0x40 [parport] port_check+0x3b/0x50 [parport] bus_for_each_dev+0x115/0x180 ? subsys_dev_iter_exit+0x20/0x20 __parport_register_driver+0x1f0/0x210 [parport] ? 0xffffffffc1150000 do_one_initcall+0xb9/0x3b5 ? perf_trace_initcall_level+0x270/0x270 ? kasan_unpoison_shadow+0x30/0x40 ? kasan_unpoison_shadow+0x30/0x40 do_init_module+0xe0/0x330 load_module+0x38eb/0x4270 ? module_frob_arch_sections+0x20/0x20 ? kernel_read_file+0x188/0x3f0 ? find_held_lock+0x6d/0xd0 ? fput_many+0x1a/0xe0 ? __do_sys_finit_module+0x162/0x190 __do_sys_finit_module+0x162/0x190 ? __ia32_sys_init_module+0x40/0x40 ? __mutex_unlock_slowpath+0xb4/0x3f0 ? wait_for_completion+0x240/0x240 ? vfs_write+0x160/0x2a0 ? lockdep_hardirqs_off+0xb5/0x100 ? mark_held_locks+0x1a/0x90 ? do_syscall_64+0x14/0x2a0 do_syscall_64+0x72/0x2a0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Reported-by: Hulk Robot Fixes: 702a4879ec33 ("spi: bitbang: Let spi_bitbang_start() take a reference to master") Signed-off-by: YueHaibing Reviewed-by: Geert Uytterhoeven Reviewed-by: Axel Lin Reviewed-by: Mukesh Ojha Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-bitbang.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c index 3aa9e6e3dac8..4ef54436b9d4 100644 --- a/drivers/spi/spi-bitbang.c +++ b/drivers/spi/spi-bitbang.c @@ -392,7 +392,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) if (ret) spi_master_put(master); - return 0; + return ret; } EXPORT_SYMBOL_GPL(spi_bitbang_start); -- 2.20.1