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AJvYcCW2jn7Kv6RYN8R643DDm753rAjUoQZLm7newnIn5Aor/1l8ZGh6lrnURDrg5yCVy3HyZJaROkGKAQ==@kvack.org X-Gm-Message-State: AOJu0Yw68gFBjDbeuU98s6orI1D4WilFJUHVggzXVa9x0SZ71G9P2YGm IYlekllLHTNzMwt9MvV3fZMn75LKPYbhkaPzBp+lz3/HwFQ8XlkA 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-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 9EB652000F X-Stat-Signature: uh3cm81as9kabtfa8mao5zkqy3rkozbe X-Rspam-User: X-HE-Tag: 1724814217-501825 X-HE-Meta: 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 jF9TFLqt 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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(-)