From patchwork Wed Aug 28 03:03:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13780381 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E37E6C5474A for ; Wed, 28 Aug 2024 03:03:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2EF2310E459; Wed, 28 Aug 2024 03:03:37 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="Dhd/cwMX"; dkim-atps=neutral Received: from mail-pf1-f176.google.com (mail-pf1-f176.google.com [209.85.210.176]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9AE9C10E459 for ; Wed, 28 Aug 2024 03:03:36 +0000 (UTC) Received: by mail-pf1-f176.google.com with SMTP id d2e1a72fcca58-714186ce2f2so4835060b3a.0 for ; Tue, 27 Aug 2024 20:03:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1724814216; x=1725419016; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=u96++TBbJ71oR+HkQgBso+tiWoljyvGONtmx4MFc6sw=; b=Dhd/cwMXgwS3oPxkQfj6sMSEDrd69nEqTdXo6k//AbDNP728ygifjnA9xOpldpxlPA DWv8ES5iz9e/Ino+x6ApiIX4s1HL+XPceQsAwZLh9MzW1ZeGDR2QDQw1DrsY4ZxiEHPT jO8ZsSm7SQP1Naqh1MQ2cGs2E+C8bNllQs9gS8wjJvjRpLEkEGTUU/1aEKT6OQ/+q/s+ 1d5EBjCoajCyO2ai80jBxd/PSsqCG2spisXUf/GJJ22Wrt5j76Zk0GUChez7nRjdo/w8 5idNPdbikatPj2pD2V3l5LC10An/RWwwhtbSZVpRy5OAXA/I6y15y0eWCHHcyCHXCaBJ 3I9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724814216; x=1725419016; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=u96++TBbJ71oR+HkQgBso+tiWoljyvGONtmx4MFc6sw=; b=oMclOoev6UH841TebBriuRGAs7Nv5AwsUvsrCYespnQ6w3ZC4h6RJaprisF45IX3sY bGr062HmLf5PRXUCwjAOnAEE/tM+sGyPWh5fsrdgxhSdM3bcjg9CfVWsDDuumx5vxBEz NANbQB/ZTc+KB5+vBFIc+iDtTn3bdAdq2Zk6QNggRgf9u2VlGDblcmqdA34UFp5FmRIt 1FCU9mioduY84i0lgTS6ROZiKc7JfXWHPdMG/Oby/1E2QKDs5JwGnnX8TVUgFwAz1J4V 09jmGhvzOaPRH012bCZPWd0ZpQw4NXpEtaSMQOy77HZhCluxL9o5QNUgnQMvILSSRenn snfg== X-Forwarded-Encrypted: i=1; AJvYcCVz2tjf7A6s2F1c9d4c/AFK5DSI0HbV2FxXcE3EvW/IwKfmTJQrdBjdGzCzqin0W8lp1EkNlZxIOfY=@lists.freedesktop.org X-Gm-Message-State: AOJu0YyMYnUigF8pnJqx26QZeE6SATYN/6bBQAipi737zQI+2F4zFQ+I 1itfRaFaXpG7CLqi/Pi/s34XEaC2qPbnqIC7caEIPx/+UqeK1lAx X-Google-Smtp-Source: AGHT+IHibExtxV8dBZTZD5JORthJOms4iDv1rvcr+QvHWcHAfAXxuXG3hLg0KOZ+K8PqosjKn4N4Iw== X-Received: by 2002:a05:6a20:9c89:b0:1c3:a63a:cef2 with SMTP id adf61e73a8af0-1cc89dc90ecmr15627538637.28.1724814215888; Tue, 27 Aug 2024 20:03:35 -0700 (PDT) Received: from localhost.localdomain ([39.144.104.43]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2d8445db8f6sm317977a91.1.2024.08.27.20.03.28 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Aug 2024 20:03:35 -0700 (PDT) From: Yafang Shao To: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org, alx@kernel.org, justinstitt@google.com, ebiederm@xmission.com, alexei.starovoitov@gmail.com, rostedt@goodmis.org, catalin.marinas@arm.com, penguin-kernel@i-love.sakura.ne.jp, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, audit@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Yafang Shao Subject: [PATCH v8 0/8] Improve the copy of task comm Date: Wed, 28 Aug 2024 11:03:13 +0800 Message-Id: <20240828030321.20688-1-laoar.shao@gmail.com> X-Mailer: git-send-email 2.30.1 (Apple Git-130) MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Using {memcpy,strncpy,strcpy,kstrdup} to copy the task comm relies on the length of task comm. Changes in the task comm could result in a destination string that is overflow. Therefore, we should explicitly ensure the destination string is always NUL-terminated, regardless of the task comm. This approach will facilitate future extensions to the task comm. As suggested by Linus [0], we can identify all relevant code with the following git grep command: git grep 'memcpy.*->comm\>' git grep 'kstrdup.*->comm\>' git grep 'strncpy.*->comm\>' git grep 'strcpy.*->comm\>' PATCH #2~#4: memcpy PATCH #5~#6: kstrdup PATCH #7~#8: strcpy Please note that strncpy() is not included in this series as it is being tracked by another effort. [1] In this series, we have removed __get_task_comm() because the task_lock() and BUILD_BUG_ON() within it are unnecessary. Suggested-by: Linus Torvalds Link: https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=psR30+CogFd4aXrThr2gsiS4g@mail.gmail.com/ [0] Changes: v7->v8: - Avoid '+1' and '-1' in string copy. (Alejandro) v6->v7: https://lore.kernel.org/all/20240817025624.13157-1-laoar.shao@gmail.com/ - Improve the comment (Alejandro) - Drop strncpy as it is being tracked by another effort (Justin) https://github.com/KSPP/linux/issues/90 [1] v5->v6: https://lore.kernel.org/linux-mm/20240812022933.69850-1-laoar.shao@gmail.com/ - Get rid of __get_task_comm() (Linus) - Use ARRAY_SIZE() in get_task_comm() (Alejandro) v4->v5: https://lore.kernel.org/all/20240804075619.20804-1-laoar.shao@gmail.com/ - Drop changes in the mm/kmemleak.c as it was fixed by commit 0b84780134fb ("mm/kmemleak: replace strncpy() with strscpy()") - Drop changes in kernel/tsacct.c as it was fixed by commmit 0fe2356434e ("tsacct: replace strncpy() with strscpy()") v3->v4: https://lore.kernel.org/linux-mm/20240729023719.1933-1-laoar.shao@gmail.com/ - Rename __kstrndup() to __kmemdup_nul() and define it inside mm/util.c (Matthew) - Remove unused local varaible (Simon) v2->v3: https://lore.kernel.org/all/20240621022959.9124-1-laoar.shao@gmail.com/ - Deduplicate code around kstrdup (Andrew) - Add commit log for dropping task_lock (Catalin) v1->v2: https://lore.kernel.org/bpf/20240613023044.45873-1-laoar.shao@gmail.com/ - Add comment for dropping task_lock() in __get_task_comm() (Alexei) - Drop changes in trace event (Steven) - Fix comment on task comm (Matus) v1: https://lore.kernel.org/all/20240602023754.25443-1-laoar.shao@gmail.com/ Yafang Shao (8): Get rid of __get_task_comm() auditsc: Replace memcpy() with strscpy() security: Replace memcpy() with get_task_comm() bpftool: Ensure task comm is always NUL-terminated mm/util: Fix possible race condition in kstrdup() mm/util: Deduplicate code in {kstrdup,kstrndup,kmemdup_nul} net: Replace strcpy() with strscpy() drm: Replace strcpy() with strscpy() drivers/gpu/drm/drm_framebuffer.c | 2 +- drivers/gpu/drm/i915/i915_gpu_error.c | 2 +- fs/exec.c | 10 ----- fs/proc/array.c | 2 +- include/linux/sched.h | 32 +++++++++++--- kernel/auditsc.c | 6 +-- kernel/kthread.c | 2 +- mm/util.c | 62 ++++++++++++--------------- net/ipv6/ndisc.c | 2 +- security/lsm_audit.c | 4 +- security/selinux/selinuxfs.c | 2 +- tools/bpf/bpftool/pids.c | 2 + 12 files changed, 66 insertions(+), 62 deletions(-)