From patchwork Mon Oct 7 14:49:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13824802 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 78159CFB441 for ; Mon, 7 Oct 2024 14:49:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0253310E0D0; Mon, 7 Oct 2024 14:49:34 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="UrDW4LnX"; dkim-atps=neutral Received: from mail-pf1-f169.google.com (mail-pf1-f169.google.com [209.85.210.169]) by gabe.freedesktop.org (Postfix) with ESMTPS id 271BD10E0D0 for ; Mon, 7 Oct 2024 14:49:32 +0000 (UTC) Received: by mail-pf1-f169.google.com with SMTP id d2e1a72fcca58-71e023635acso769132b3a.2 for ; Mon, 07 Oct 2024 07:49:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1728312571; x=1728917371; 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=LUiVT68fLR3vW4CyEtRR57v0fZ51pf3YQeR56Ep4krg=; b=UrDW4LnX40v1nXSnepbhQQE/SKcciubdcxloSfM0UJFqBLgrah4x+lAXXDpNi8ZOB1 AYeIZnZgeP+WVWML5Fp+/zoqt+SykHsBTZV2KDclBIjKsG6qN2F/xS0w5AZF+hqpxPO7 dI5hPWNQd9xSKqa7SEXVVcjDm821CwDL746p+B0nXW+va5V++37puQK0mPCSW5uL6Rov NqhpWlmC3Izcnde+6/O2UkA0O88XKDICW1ynO/1mdSfONpaWrrRwRCWCWyyKYjQElS6S frBGGIrl9iY06AKHN0uSXbpK+2u0lGuz6Sd/HDWOIJvJEOJY7dtSK5yHDvPOgJSln48M mcrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1728312571; x=1728917371; 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=LUiVT68fLR3vW4CyEtRR57v0fZ51pf3YQeR56Ep4krg=; b=oX1OxxBion0ldLHuKrAsPl191rEQCuZx3GZ2At0h3UaoLtrGMWAIsH+Ui3s5LxwWq/ MMk+ZAQNENOPmvaYP7+RvCe/D6Mussst0Vyl7ewE/H/X/qidciI97/gAA8iSslVA9Hq/ Os26nGm+mRY8LNuvJ0+Xg2+U2WGLoaac9H8+JbMRF0HVPAILJ1CQhxxxykRyy47C2WWU mr3QjAnENAy35tjbI9WniomBGXIgInN3BDjpP5b84IOg8OWhbfHDhYSBweso9kPlNas6 vyoR9LkNaNv94rnogfC3BXMbvHfAau9ab4P8Yp4Y1SW79JjBeQFV8e+FQ4miYWfBUC+1 sUVA== X-Forwarded-Encrypted: i=1; AJvYcCWAJkk3Jl4s0KWXXQoIzyBK252k4HrRTLCCVeLhDLZTavkqyHHPtWGFsgAd34Ra8E9is8sZ73K4e1g=@lists.freedesktop.org X-Gm-Message-State: AOJu0YxtqzLd3BJHISnKT0wKFlj2PIL2qVAIsh49WqhnY6BzTPionTTu X1Pk4UIFXv6o++uP2zgXf0U8I0Oge+sa0II0AFtHCTlfPuvz6HM4 X-Google-Smtp-Source: AGHT+IFd5G5JZb9zGuck27vY3G5rfm6RRd7wrvlQcG7A8r1xXm54v9yJmOzv7wLCL4FHuPfrgLQA4A== X-Received: by 2002:a05:6a00:3a14:b0:717:9768:a4f0 with SMTP id d2e1a72fcca58-71de22eb62bmr20503670b3a.0.1728312571513; Mon, 07 Oct 2024 07:49:31 -0700 (PDT) Received: from localhost.localdomain ([223.104.210.43]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-71df0d7cf82sm4466432b3a.200.2024.10.07.07.49.22 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Oct 2024 07:49:30 -0700 (PDT) From: Yafang Shao To: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org, keescook@chromium.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 v9 0/7] Improve the copy of task comm Date: Mon, 7 Oct 2024 22:49:04 +0800 Message-Id: <20241007144911.27693-1-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: strcpy Please note that strncpy() is not included in this series as it is being tracked by another effort. [1] task_lock() is removed from get_task_comm() as it is unnecessary. Suggested-by: Linus Torvalds Link: https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=psR30+CogFd4aXrThr2gsiS4g@mail.gmail.com/ [0] Changes: v8->v9: - Keep the BUILD_BUG_ON() in get_task_comm() (Kees) - Keep strscpy_pad() in get_task_comm() (Kees) - Replace more strcpy() with strscpy() in drivers/gpu/drm/i915/i915_gpu_error.c (Justin) - Fix typos and commit improvement in patch #5 (Andy) - Drop the change in net as it was fixed by b19f69a95830 ("net/ipv6: replace deprecated strcpy with strscpy") v7->v8: https://lore.kernel.org/all/20240828030321.20688-1-laoar.shao@gmail.com/ - 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 commit 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 variable (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 (7): 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} drm: Replace strcpy() with strscpy() drivers/gpu/drm/drm_framebuffer.c | 2 +- drivers/gpu/drm/i915/i915_gpu_error.c | 6 +-- fs/exec.c | 10 ----- fs/proc/array.c | 2 +- include/linux/sched.h | 28 +++++++++--- kernel/auditsc.c | 6 +-- kernel/kthread.c | 2 +- mm/util.c | 62 ++++++++++++--------------- security/lsm_audit.c | 4 +- security/selinux/selinuxfs.c | 2 +- tools/bpf/bpftool/pids.c | 2 + 11 files changed, 63 insertions(+), 63 deletions(-)