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 A02AEC4646B for ; Wed, 26 Jun 2019 03:49:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B114205ED for ; Wed, 26 Jun 2019 03:49:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561520985; bh=UFcJ5ROrrZtcdmtox+gU2VxAuKCTi0iW/h7Wdx8cd98=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ieDTXJ+VlTQB/UvjJw4xcGqi/hj1pwxgztwJWHLpTk6GZJqXlWEgsojH/nsQcEyJl nvsY8FThDnn56qxiNQTdHD4+DrjEdfXbtwy4JTsB5zY6ebHdJHxuQMMr7y18cNcS4h MIADPXM3a2k+sPzGmrycjqGlZAN+AzNFBxdo+FL0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727817AbfFZDtk (ORCPT ); Tue, 25 Jun 2019 23:49:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:54856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727362AbfFZDnf (ORCPT ); Tue, 25 Jun 2019 23:43:35 -0400 Received: from sasha-vm.mshome.net (mobile-107-77-172-74.mobile.att.net [107.77.172.74]) (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 0B02C216E3; Wed, 26 Jun 2019 03:43:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561520613; bh=UFcJ5ROrrZtcdmtox+gU2VxAuKCTi0iW/h7Wdx8cd98=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t+tNxe4ngtIYYmLPZKzPczShRiBTF7Z9fqiCbOEfGIutIJ+wVBeTrDQ4A4e+acwFe jp1Y66kctlAa+wjGBIZrSTMLdJxKlGIB0iFIaZk16FVJ2numR8aHseax1sGKqKrnZ3 A9Kl8K8EMMIl1mnZOtvG0B0MBcp+i0HPLHoBI240= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wei Li , Steven Rostedt , Sasha Levin Subject: [PATCH AUTOSEL 5.1 51/51] ftrace: Fix NULL pointer dereference in free_ftrace_func_mapper() Date: Tue, 25 Jun 2019 23:41:07 -0400 Message-Id: <20190626034117.23247-51-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190626034117.23247-1-sashal@kernel.org> References: <20190626034117.23247-1-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: Wei Li [ Upstream commit 04e03d9a616c19a47178eaca835358610e63a1dd ] The mapper may be NULL when called from register_ftrace_function_probe() with probe->data == NULL. This issue can be reproduced as follow (it may be covered by compiler optimization sometime): / # cat /sys/kernel/debug/tracing/set_ftrace_filter #### all functions enabled #### / # echo foo_bar:dump > /sys/kernel/debug/tracing/set_ftrace_filter [ 206.949100] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 206.952402] Mem abort info: [ 206.952819] ESR = 0x96000006 [ 206.955326] Exception class = DABT (current EL), IL = 32 bits [ 206.955844] SET = 0, FnV = 0 [ 206.956272] EA = 0, S1PTW = 0 [ 206.956652] Data abort info: [ 206.957320] ISV = 0, ISS = 0x00000006 [ 206.959271] CM = 0, WnR = 0 [ 206.959938] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000419f3a000 [ 206.960483] [0000000000000000] pgd=0000000411a87003, pud=0000000411a83003, pmd=0000000000000000 [ 206.964953] Internal error: Oops: 96000006 [#1] SMP [ 206.971122] Dumping ftrace buffer: [ 206.973677] (ftrace buffer empty) [ 206.975258] Modules linked in: [ 206.976631] Process sh (pid: 281, stack limit = 0x(____ptrval____)) [ 206.978449] CPU: 10 PID: 281 Comm: sh Not tainted 5.2.0-rc1+ #17 [ 206.978955] Hardware name: linux,dummy-virt (DT) [ 206.979883] pstate: 60000005 (nZCv daif -PAN -UAO) [ 206.980499] pc : free_ftrace_func_mapper+0x2c/0x118 [ 206.980874] lr : ftrace_count_free+0x68/0x80 [ 206.982539] sp : ffff0000182f3ab0 [ 206.983102] x29: ffff0000182f3ab0 x28: ffff8003d0ec1700 [ 206.983632] x27: ffff000013054b40 x26: 0000000000000001 [ 206.984000] x25: ffff00001385f000 x24: 0000000000000000 [ 206.984394] x23: ffff000013453000 x22: ffff000013054000 [ 206.984775] x21: 0000000000000000 x20: ffff00001385fe28 [ 206.986575] x19: ffff000013872c30 x18: 0000000000000000 [ 206.987111] x17: 0000000000000000 x16: 0000000000000000 [ 206.987491] x15: ffffffffffffffb0 x14: 0000000000000000 [ 206.987850] x13: 000000000017430e x12: 0000000000000580 [ 206.988251] x11: 0000000000000000 x10: cccccccccccccccc [ 206.988740] x9 : 0000000000000000 x8 : ffff000013917550 [ 206.990198] x7 : ffff000012fac2e8 x6 : ffff000012fac000 [ 206.991008] x5 : ffff0000103da588 x4 : 0000000000000001 [ 206.991395] x3 : 0000000000000001 x2 : ffff000013872a28 [ 206.991771] x1 : 0000000000000000 x0 : 0000000000000000 [ 206.992557] Call trace: [ 206.993101] free_ftrace_func_mapper+0x2c/0x118 [ 206.994827] ftrace_count_free+0x68/0x80 [ 206.995238] release_probe+0xfc/0x1d0 [ 206.995555] register_ftrace_function_probe+0x4a8/0x868 [ 206.995923] ftrace_trace_probe_callback.isra.4+0xb8/0x180 [ 206.996330] ftrace_dump_callback+0x50/0x70 [ 206.996663] ftrace_regex_write.isra.29+0x290/0x3a8 [ 206.997157] ftrace_filter_write+0x44/0x60 [ 206.998971] __vfs_write+0x64/0xf0 [ 206.999285] vfs_write+0x14c/0x2f0 [ 206.999591] ksys_write+0xbc/0x1b0 [ 206.999888] __arm64_sys_write+0x3c/0x58 [ 207.000246] el0_svc_common.constprop.0+0x408/0x5f0 [ 207.000607] el0_svc_handler+0x144/0x1c8 [ 207.000916] el0_svc+0x8/0xc [ 207.003699] Code: aa0003f8 a9025bf5 aa0103f5 f946ea80 (f9400303) [ 207.008388] ---[ end trace 7b6d11b5f542bdf1 ]--- [ 207.010126] Kernel panic - not syncing: Fatal exception [ 207.011322] SMP: stopping secondary CPUs [ 207.013956] Dumping ftrace buffer: [ 207.014595] (ftrace buffer empty) [ 207.015632] Kernel Offset: disabled [ 207.017187] CPU features: 0x002,20006008 [ 207.017985] Memory Limit: none [ 207.019825] ---[ end Kernel panic - not syncing: Fatal exception ]--- Link: http://lkml.kernel.org/r/20190606031754.10798-1-liwei391@huawei.com Signed-off-by: Wei Li Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin --- kernel/trace/ftrace.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 045e7f46a74a..2469d54b3e43 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4230,10 +4230,13 @@ void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, struct ftrace_func_entry *entry; struct ftrace_func_map *map; struct hlist_head *hhd; - int size = 1 << mapper->hash.size_bits; - int i; + int size, i; + + if (!mapper) + return; if (free_func && mapper->hash.count) { + size = 1 << mapper->hash.size_bits; for (i = 0; i < size; i++) { hhd = &mapper->hash.buckets[i]; hlist_for_each_entry(entry, hhd, hlist) { -- 2.20.1