From patchwork Sat Aug 17 02:56:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13766940 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 13D82C3DA4A for ; Sat, 17 Aug 2024 02:56:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 92DC210E03D; Sat, 17 Aug 2024 02:56:49 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="aoy/deeV"; dkim-atps=neutral Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) by gabe.freedesktop.org (Postfix) with ESMTPS id EF61410E03D for ; Sat, 17 Aug 2024 02:56:47 +0000 (UTC) Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-202146e9538so7971005ad.3 for ; Fri, 16 Aug 2024 19:56:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1723863407; x=1724468207; 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=rKgZtG9uOqD3DFxRKcQkjZTQLILEzoQhivhfaU9Nqo4=; b=aoy/deeV/N9fKVr7zmbi2jPCnnXH2nQ+6SXyMenSX7qdjYITO2Tuy7pqyGnI8QWQ/S 5hzGL09PcksFme/kkB+mnCixPyx/GqFTdYn7h5Bx5YZzAw9ZGvxKZ02CiSziaX66zNvW jitc1KPBqkULW0tOPxmUo7dJeeD6jziFdVqqp0d5OW1deRZi8g7kpzgZQM8boOCT+vAX EDEQURLL09LBOoFEnS8ecvWkVoEWuxuce+FSfakb4Fz5odDgNyE4H3VWC44zEMhkntLY 3BTLkWbQdHYNl2Qo0rfpoCEGzKbM9vRgVlg7GJmc9pJeqD5yvuxW/zVVwgGglWM803PQ 5ntA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723863407; x=1724468207; 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=rKgZtG9uOqD3DFxRKcQkjZTQLILEzoQhivhfaU9Nqo4=; b=uGH/Gw0pTTD/R6cf2Lx67We2P2DL4Q5rFvfO5Kj/E9lacvF3xm25c8mcH0dxjhoVUd pQmHT8Q2ZoxsETBMUMDs76Y5yMhO5G8i9YYNjYyYeYswR9/tD/a6+zDxlsOVw0CUtxOO hU27UOO+Rq4r/n6Owb2AFKHn04mVouWly6QT47Lk5Xr2dGMVYWAFB1WS+d2BXgTB4Sgg sXvjdxG1MIdSerlYgiOCeMfXYblvHIL4CY4ib+fuCv1Q+1pUpMDqTKb0by7ZqQzUQnEN JMv9h9o27klB+ALKEGEWOqfgM6FYisqhGKU7wVeTRW8/h/ZOdK++zPlX1x0npx1xSk31 qWoA== X-Forwarded-Encrypted: i=1; AJvYcCWR91hrlYy1Uo5hUSp9mF2qf3q5F2x/ajDF6E/xNHECXegAgVJetMKjrf1C1XkSAUrJAfq7R2JSShjwwDNyWfpSLRpMXIlku0AWbrLUeAb7 X-Gm-Message-State: AOJu0YyKuC10OdVzwHwUhttY7xSRfG2HJlSaB0pffGyeavMYvKIwPaJS QWyhz0VdF/Ah7iiyuMuxSWOR+A+T/fNoIhu8+YTLWLwLDdp8cjQa X-Google-Smtp-Source: AGHT+IEbPGpqoRSYF8jBgPK+pTBiTQRphrHbJ0rUSgdEvQgjtWO3Wff4DwqW4cJKQwtvK2mv0b1kNQ== X-Received: by 2002:a17:903:124e:b0:1f7:1b08:dda9 with SMTP id d9443c01a7336-20203e50e27mr63144585ad.8.1723863407171; Fri, 16 Aug 2024 19:56:47 -0700 (PDT) Received: from localhost.localdomain ([183.193.177.10]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-201f031c5e1sm31801785ad.94.2024.08.16.19.56.39 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 16 Aug 2024 19:56:46 -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 v7 0/8] Improve the copy of task comm Date: Sat, 17 Aug 2024 10:56:16 +0800 Message-Id: <20240817025624.13157-1-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: v6->v7: - 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 | 61 ++++++++++++--------------- net/ipv6/ndisc.c | 2 +- security/lsm_audit.c | 4 +- security/selinux/selinuxfs.c | 2 +- tools/bpf/bpftool/pids.c | 2 + 12 files changed, 65 insertions(+), 62 deletions(-)