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=-10.1 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=unavailable 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 54943C76196 for ; Fri, 19 Jul 2019 04:02:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B98C21851 for ; Fri, 19 Jul 2019 04:02:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563508930; bh=9GAUxEDGrz6p+X4090gdjhdKhYDC2727M0VEUVEW7Zk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=trNprA7AOVQqiwLdHBf5kgFYlA0MgKveQskBsvHDSwLCJEqeEC08H/fjjUSApsIXi vec4Zbj4Ws2cpSL9kfgFT/okGnQJanyXhz4AEbBHa3YRpFnfX0HXaj+Hr/cm+YvwAN xuvQMhLHaAthOBUJWvxjAFl7WZx1ama5MxU80TD4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729866AbfGSECJ (ORCPT ); Fri, 19 Jul 2019 00:02:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:33698 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729702AbfGSEBz (ORCPT ); Fri, 19 Jul 2019 00:01:55 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 3F1A521873; Fri, 19 Jul 2019 04:01:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563508914; bh=9GAUxEDGrz6p+X4090gdjhdKhYDC2727M0VEUVEW7Zk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P1bvtev9IcCHwx/bTh9HILe944CP2yEbgTErDWs2hT5DpSX8ktcrcOtcxlBnU9qBv 9ays0IlEp5o6wxMIUlgxL69Efwd76urRw+nt0Vqu8/PGLNBads84SX2vHyOdmjd5kf Nqgz3A4YggRPXpLlmgxo5HGKzdFx8D8+zeU3UQ+k= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dmitry Vyukov , Catalin Marinas , Andrew Morton , Linus Torvalds , Sasha Levin , linux-mm@kvack.org Subject: [PATCH AUTOSEL 5.2 156/171] mm/kmemleak.c: fix check for softirq context Date: Thu, 18 Jul 2019 23:56:27 -0400 Message-Id: <20190719035643.14300-156-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190719035643.14300-1-sashal@kernel.org> References: <20190719035643.14300-1-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: Dmitry Vyukov [ Upstream commit 6ef9056952532c3b746de46aa10d45b4d7797bd8 ] in_softirq() is a wrong predicate to check if we are in a softirq context. It also returns true if we have BH disabled, so objects are falsely stamped with "softirq" comm. The correct predicate is in_serving_softirq(). If user does cat from /sys/kernel/debug/kmemleak previously they would see this, which is clearly wrong, this is system call context (see the comm): unreferenced object 0xffff88805bd661c0 (size 64): comm "softirq", pid 0, jiffies 4294942959 (age 12.400s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 ff ff ff ff 00 00 00 00 ................ 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................ backtrace: [<0000000007dcb30c>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<0000000007dcb30c>] slab_post_alloc_hook mm/slab.h:439 [inline] [<0000000007dcb30c>] slab_alloc mm/slab.c:3326 [inline] [<0000000007dcb30c>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 [<00000000969722b7>] kmalloc include/linux/slab.h:547 [inline] [<00000000969722b7>] kzalloc include/linux/slab.h:742 [inline] [<00000000969722b7>] ip_mc_add1_src net/ipv4/igmp.c:1961 [inline] [<00000000969722b7>] ip_mc_add_src+0x36b/0x400 net/ipv4/igmp.c:2085 [<00000000a4134b5f>] ip_mc_msfilter+0x22d/0x310 net/ipv4/igmp.c:2475 [<00000000d20248ad>] do_ip_setsockopt.isra.0+0x19fe/0x1c00 net/ipv4/ip_sockglue.c:957 [<000000003d367be7>] ip_setsockopt+0x3b/0xb0 net/ipv4/ip_sockglue.c:1246 [<000000003c7c76af>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616 [<000000000c1aeb23>] sock_common_setsockopt+0x3e/0x50 net/core/sock.c:3130 [<000000000157b92b>] __sys_setsockopt+0x9e/0x120 net/socket.c:2078 [<00000000a9f3d058>] __do_sys_setsockopt net/socket.c:2089 [inline] [<00000000a9f3d058>] __se_sys_setsockopt net/socket.c:2086 [inline] [<00000000a9f3d058>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086 [<000000001b8da885>] do_syscall_64+0x7c/0x1a0 arch/x86/entry/common.c:301 [<00000000ba770c62>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 now they will see this: unreferenced object 0xffff88805413c800 (size 64): comm "syz-executor.4", pid 8960, jiffies 4294994003 (age 14.350s) hex dump (first 32 bytes): 00 7a 8a 57 80 88 ff ff e0 00 00 01 00 00 00 00 .z.W............ 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................ backtrace: [<00000000c5d3be64>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<00000000c5d3be64>] slab_post_alloc_hook mm/slab.h:439 [inline] [<00000000c5d3be64>] slab_alloc mm/slab.c:3326 [inline] [<00000000c5d3be64>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 [<0000000023865be2>] kmalloc include/linux/slab.h:547 [inline] [<0000000023865be2>] kzalloc include/linux/slab.h:742 [inline] [<0000000023865be2>] ip_mc_add1_src net/ipv4/igmp.c:1961 [inline] [<0000000023865be2>] ip_mc_add_src+0x36b/0x400 net/ipv4/igmp.c:2085 [<000000003029a9d4>] ip_mc_msfilter+0x22d/0x310 net/ipv4/igmp.c:2475 [<00000000ccd0a87c>] do_ip_setsockopt.isra.0+0x19fe/0x1c00 net/ipv4/ip_sockglue.c:957 [<00000000a85a3785>] ip_setsockopt+0x3b/0xb0 net/ipv4/ip_sockglue.c:1246 [<00000000ec13c18d>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616 [<0000000052d748e3>] sock_common_setsockopt+0x3e/0x50 net/core/sock.c:3130 [<00000000512f1014>] __sys_setsockopt+0x9e/0x120 net/socket.c:2078 [<00000000181758bc>] __do_sys_setsockopt net/socket.c:2089 [inline] [<00000000181758bc>] __se_sys_setsockopt net/socket.c:2086 [inline] [<00000000181758bc>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086 [<00000000d4b73623>] do_syscall_64+0x7c/0x1a0 arch/x86/entry/common.c:301 [<00000000c1098bec>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Link: http://lkml.kernel.org/r/20190517171507.96046-1-dvyukov@gmail.com Signed-off-by: Dmitry Vyukov Acked-by: Catalin Marinas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/kmemleak.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 9dd581d11565..3e147ea83182 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -575,7 +575,7 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size, if (in_irq()) { object->pid = 0; strncpy(object->comm, "hardirq", sizeof(object->comm)); - } else if (in_softirq()) { + } else if (in_serving_softirq()) { object->pid = 0; strncpy(object->comm, "softirq", sizeof(object->comm)); } else { -- 2.20.1