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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41691C4706C for ; Tue, 16 Jan 2024 11:16:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A73A36B0075; Tue, 16 Jan 2024 06:16:51 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A24126B0078; Tue, 16 Jan 2024 06:16:51 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8E98E6B007B; Tue, 16 Jan 2024 06:16:51 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 7E6326B0075 for ; Tue, 16 Jan 2024 06:16:51 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 4881D1C0E91 for ; Tue, 16 Jan 2024 11:16:51 +0000 (UTC) X-FDA: 81684921822.15.A4A0FEB Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf05.hostedemail.com (Postfix) with ESMTP id 70460100023 for ; Tue, 16 Jan 2024 11:16:48 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=E9W+EX4i; spf=pass (imf05.hostedemail.com: domain of brauner@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=brauner@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1705403808; h=from:from:sender: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:dkim-signature; bh=iRFDmaz6+LTBSLuIGye051mk6kPzDm386C+xlTbz1WM=; b=PnkZBlIc+6qkEKosT36rbucBBmq4xP1ZPIIo1OAwp3b2/acMlfr6k82k7B74OPagD0i7R4 gnC1N3gVO/TqvxmNxvMR0p7P/RqY1LDDQ/Eb1//Hr4cnD9jW80MNUW821ovzDC0iMEUSQX p7Pu6WF2RoEh852TLKewNWbcW6T9y2o= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=E9W+EX4i; spf=pass (imf05.hostedemail.com: domain of brauner@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=brauner@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1705403808; a=rsa-sha256; cv=none; b=D87KoZ7yJpADEi/THXHSvr46oA54gzdjJh2wj27QoJFMAiDmXcZaYZ1uSKyAr6BWkDrd4d JP3Ik58zv4/eo21QYgYxHh38GA+7m8iXFMb573VSO0ieLiIB1z2of3o0LfYNUwE4o0h9Re uo4arK2pwt09r8cDYrV+KvP31v+r3Eo= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id E0159B80DBD; Tue, 16 Jan 2024 11:16:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F180BC43390; Tue, 16 Jan 2024 11:16:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705403806; bh=12enHdEQYZDZ3C3XmaZ8fBP/gSRyAW+Pnt48jGr3N8k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E9W+EX4iPCkfSggIM6tLa4X83v9iG3ko2x80brb3RSZ3tFwDl/PWDQ7B/ybrZJSbG Q0oIghDVEAbqIQRG06yYr+bMYbg3w/FyK+zUHP0Fqz2liEH0y9bUKEqco+6LFNNdFK VjLgJEKwmoGawPxcBgDFZBtXSGxoG5wXfae3nbweJLAxn8V2Lxgm/PJxx1jOZ5IfME ohvRqWe1YOLrTPFuVu1TFsVcYdbZhknRYgr5fUI4ZBtefv6PrPwWM3n/jZXDzeKZXM Xu9cJ7NbShP6gooMahRvQpnA4p+qJbZq1AYyRh9yp0bVaUv6DQyXfmYvKbTYPzuPUt jfCH0OeErIgng== From: Christian Brauner To: Baolin Wang Cc: Christian Brauner , willy@infradead.org, viro@zeniv.linux.org.uk, jack@suse.cz, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: Re: [PATCH] fs: improve dump_mapping() robustness Date: Tue, 16 Jan 2024 12:16:35 +0100 Message-ID: <20240116-privat-zeitplan-21db23926f45@brauner> X-Mailer: git-send-email 2.43.0 In-Reply-To: <937ab1f87328516821d39be672b6bc18861d9d3e.1705391420.git.baolin.wang@linux.alibaba.com> References: <937ab1f87328516821d39be672b6bc18861d9d3e.1705391420.git.baolin.wang@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" X-Developer-Signature: v=1; a=openpgp-sha256; l=1789; i=brauner@kernel.org; h=from:subject:message-id; bh=12enHdEQYZDZ3C3XmaZ8fBP/gSRyAW+Pnt48jGr3N8k=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMaQuS53GOe9+OOsFtl72fJE94u7z6uW7Gc+KuBakhl9Iu lUxYdbKjlIWBjEuBlkxRRaHdpNwueU8FZuNMjVg5rAygQxh4OIUgInM8mNk2Mn+2tRK0n3Lte8r F+SXnLf++N5bYuE8JUnn1IUdTxLqJjH8M8/xFLd2faYb+WfisRkq55O5Li61N03cF5TaaBWq17i cEQA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 70460100023 X-Rspam-User: X-Stat-Signature: ume4uzp16npi9s8gyw9o6xms6ec9npf7 X-Rspamd-Server: rspam01 X-HE-Tag: 1705403808-964333 X-HE-Meta: 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 RMNDPHLZ rqG16v8a+QPG6o0oAxpMRJZ57RXn57Bmr8hiLRH+DnYNoZPTCAlJZx4eHDgUMZyWTpOEKw5uWbLdjCvRnwKbNy5xYmiF2z7ysv55rvY7oVVcd4eXVhujE8mDGJKKA4MQfyAbSjujyG2Ik+bGobna9aQX319UxjopEg5kulOgyCYUt8wTKexaNZiam8ZdETibsLv1QbooAgZC2+BNugnAPU+OMBb7mYD3Jhmzsv1wz6p3KdDlHMPU2vaOeZOLaJgUd8pIuGnI6pPJpFLEVHyqDWw/gsxd4afdPIkWl X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, 16 Jan 2024 15:53:35 +0800, Baolin Wang wrote: > We met a kernel crash issue when running stress-ng testing, and the > system crashes when printing the dentry name in dump_mapping(). > > Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 > pc : dentry_name+0xd8/0x224 > lr : pointer+0x22c/0x370 > sp : ffff800025f134c0 > ...... > Call trace: > dentry_name+0xd8/0x224 > pointer+0x22c/0x370 > vsnprintf+0x1ec/0x730 > vscnprintf+0x2c/0x60 > vprintk_store+0x70/0x234 > vprintk_emit+0xe0/0x24c > vprintk_default+0x3c/0x44 > vprintk_func+0x84/0x2d0 > printk+0x64/0x88 > __dump_page+0x52c/0x530 > dump_page+0x14/0x20 > set_migratetype_isolate+0x110/0x224 > start_isolate_page_range+0xc4/0x20c > offline_pages+0x124/0x474 > memory_block_offline+0x44/0xf4 > memory_subsys_offline+0x3c/0x70 > device_offline+0xf0/0x120 > ...... > > [...] Seems fine for debugging purposes. Let me know if this needs to go through somewhere else. --- Applied to the vfs.misc branch of the vfs/vfs.git tree. Patches in the vfs.misc branch should appear in linux-next soon. Please report any outstanding bugs that were missed during review in a new review to the original patch series allowing us to drop it. It's encouraged to provide Acked-bys and Reviewed-bys even though the patch has now been applied. If possible patch trailers will be updated. Note that commit hashes shown below are subject to change due to rebase, trailer updates or similar. If in doubt, please check the listed branch. tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git branch: vfs.misc [1/1] fs: improve dump_mapping() robustness https://git.kernel.org/vfs/vfs/c/30a1b9d12728