From patchwork Mon Aug 12 02:29:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13760017 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 191E9C3DA4A for ; Mon, 12 Aug 2024 02:30:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 72B9C10E032; Mon, 12 Aug 2024 02:30:05 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="cehAI+Ca"; dkim-atps=neutral Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5437D10E032 for ; Mon, 12 Aug 2024 02:30:04 +0000 (UTC) Received: by mail-pl1-f173.google.com with SMTP id d9443c01a7336-1fc569440e1so35471975ad.3 for ; Sun, 11 Aug 2024 19:30:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1723429804; x=1724034604; 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=CPcfP+fHyMLz6sCkXjXj/fN1cAsrryKdxQYaf/+RRmQ=; b=cehAI+CaHWMTXWKeG5TqGktDesyVDieZWUOAp+2bPVw4WrRlIdcJ30wsYj532NY3gm ckKgSEAJL2A/jVqaVPesmO/GH2+hawZDaq6ZPE9QxFSFe8QA2je4sk/VLmop7XWmKacS n8oKSwjTqM9QdvEx6amzzOcBFs66sx5uUEDP2EnrIJ2nm5Ul2eVwHrxK2CKu0gpBawTb SRnuu8wKkKAx0QxrNffu5YuKyL8QsdY57IUy/jBfP3iCuzXSO2ppbMu/8EUs7Mu9AGEI GxOQNbOmjPQ/HBV+DOTZ/UffqO469rCDOCmPzGu72+EpDRAApGPGt1YHuFACNWAWPJ5h e4Tw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723429804; x=1724034604; 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=CPcfP+fHyMLz6sCkXjXj/fN1cAsrryKdxQYaf/+RRmQ=; b=eD2UmzgR54l45k+baarT3C5gNtf9e4V3Ngt+gycEYC+lRUG/PspCaCevB4HNPaqHAn DDAOi61BXGliJLB2jDb6CP8vaUBeN2NfuGZ/Ikv8E3vWewg4IRvp0uYhQzn4CyyW8t+G uttnZFigm8YaLWazev0CklzUhwbTjU8/e1hTXBo1Qt02EbNjLhJaW2dbxwYwXXvlmdZG MNR7xQ1Se6dHSLAY/VkmFCsnvHtDrGx/qsvknpfEo8IpqttzTR1n54avRqcYZqdk9268 Bkk/hnX0vRpDYkdnZdtPLUEtBZ5FXchChLWASPFuguLYr/tuqViBQ0Gzbq8OUas5SUbj a3ZQ== X-Forwarded-Encrypted: i=1; AJvYcCWOVsN53xGuf/MqHBOEpzfsVJt5rmk6CdN52g8fSmnwwFI4W2teyCU5+UB5U2SW3UXq6lnDzMGepmTcVf/gf1pi/OsrGq2MZ7kjtfpB7RPB X-Gm-Message-State: AOJu0Yx4WGL1YZXdw2kyhu3oJyuDVrwLemGr/4qyhsSO+Eg7CvqeSXai rSpJEJVBvlNWtSzV3BJrkVEbO82PUG0zR+63v4FUhy0zDbvqAvbF X-Google-Smtp-Source: AGHT+IHWjfWk9Yvp8Xz47EmfqTOyYIqZTpLYHww0hZawPQZt6bgoSLmdtP7yW5PiZUmHJmuoGirzew== X-Received: by 2002:a17:902:ce03:b0:1fb:7b01:7980 with SMTP id d9443c01a7336-200ae250234mr122466755ad.0.1723429803589; Sun, 11 Aug 2024 19:30:03 -0700 (PDT) Received: from localhost.localdomain ([39.144.39.162]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-200bb9fed69sm27884765ad.188.2024.08.11.19.29.54 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 11 Aug 2024 19:30:02 -0700 (PDT) From: Yafang Shao To: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org, 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 v6 0/9] Improve the copy of task comm Date: Mon, 12 Aug 2024 10:29:24 +0800 Message-Id: <20240812022933.69850-1-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: strncpy PATCH #8~#9: strcpy 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: v5->v6: - 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) Yafang Shao (9): 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} tracing: Replace strncpy() with strscpy() 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 | 31 +++++++++++--- kernel/auditsc.c | 6 +-- kernel/kthread.c | 2 +- kernel/trace/trace.c | 2 +- kernel/trace/trace_events_hist.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 + 14 files changed, 66 insertions(+), 64 deletions(-)