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: 13766958 Received: from mail-pl1-f175.google.com (mail-pl1-f175.google.com [209.85.214.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0ACC2EEA9; Sat, 17 Aug 2024 02:56:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.175 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723863409; cv=none; b=iLjUvmxcNjWYah9SZLsbta215GBhyuZ91hr737o4KGpIkfpMxsKgEsSgkM9aHaa6jQ9+fOvyCmoce+BocU9f5oZThRE7kapjhrl2JkdG75it/QF5Wbzz8BLpBcQx1Qth7g1Sjrmal7wsZMlLiYyVRZ1rTN0o1WJNWTUrAgD0ug0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723863409; c=relaxed/simple; bh=+jKitb4HkbCFufAiexrmRMipOSoKL+6Eqar2mQ6apRA=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=VNzXMwoIQnbxhSAn8X/SQiETs6M3yFp+iTA5Xsp9bfQvbgtnlljYTcaLU7pADnAmyPPmitpQxqMDM+Sq051NwDTcTp4s7WxBML39HHFKfZksw4YBeF1F9H6QJ5CjvOC61RB/G9x2Za44KEgGlky/Q6YQTgZOGBlAcBIY+Z+TSzE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=AeAOtq7b; arc=none smtp.client-ip=209.85.214.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AeAOtq7b" Received: by mail-pl1-f175.google.com with SMTP id d9443c01a7336-2021a99af5eso3132755ad.1; 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=vger.kernel.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=AeAOtq7bWuoSSO0yj2nCikUif0Lsq2DVexFN4MXYcuW1CaCcGMIeL+szogLsrbG+P8 8W1SfycMZgZxCuP2Rh9vgdgBg/FNJ0DWThDUsUTOBUX4Dm0OoCt/Zmb7Nnb16UtEyY0B 1LpPidN42ifDf0c6BQgW7y1Le+76JauDFlF2ZoAjWWz7X/BYYS+SfnV1unSSThdZtIQa wOPvuqUOEL/V7GL1jauEjSEzj5EEEp1V6zxOACD5pLnfEOYwbZ3G9lX1csRIoaxHaGTw uGdMBMBv4lvLTBGUr9Sq7UuxvH8NvAJ+R10IUpJZin5d1lPNn3HjqdaNOdA6tf8MIdby ogLg== 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=rpHZYXdqOJKGOHSV2CjrMVm0+w3SuLQNLQI0qTlJhvZBvLVoxvRAxzqh1/1obHEdfZ /p6SXr8sOCZ3CaloWNukbQBQKz6BGeJDJLZrBqfXgMSRVb6tPI5gO3Rn30VBOBpMAMc+ jzma2tsz4NuW7bcaquq9agd5h1QE8TmxbcxZVtCdH3jq+AOuBysZYBlfO9a4W1uMt1YF ujetsh+aSLUH0/VxMekw5p1Q/g5f2WD4uP9O3TYFdDgUKcjDTVHkQ1L1iUEMrd0S4LGM bvFYfnfwirJuhEN4hBG/tyPII2J33ehqHaOT/BcM+RvRqZqQSCFCkhXBx1iGqEAx2fRz VJ8Q== X-Forwarded-Encrypted: i=1; AJvYcCU4l18vrccTxSZbnLmVu7mD8aB4sXFBd/GPYGdbTR7sAD5Hw4FOJXSnyEGDCSvqy81HwLiT7vrsjyBmIcyctm+UumpydSuage72ilFbHim3yTNNL6NoAbf7Qlz+XlvoP/sa7kjk+18OTwXLV/Dal3hwX04d1ivgIkzEkL6RplRiQp2i5SUb2JjpMtrHy7ddD+xh5wXXkH9aCj4+zO1Z6CMGYRBhAaKsvg1GJ/ymrEZjiJwtQjAiuh6GUNyY8UwH7lz79fwiXRwHHuaZarg/DqvdyrzfH73P19MksKL2o+7sMahzE2kP4zUpg9fgA0bOng3vXC5RLA== X-Gm-Message-State: AOJu0Yz3wF3VKUbRcrV95ImbRYwrpFpEpAFBscnn+qUYqPzxFGk6HnSg 1AJQPLxoQxpalFJIJ922tv8qPn+xlZFflrUmLChc+3MO4+CNsntK 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) Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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(-)