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Tue, 27 Aug 2024 20:03:59 -0700 (PDT) Received: from localhost.localdomain ([39.144.104.43]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2d8445db8f6sm317977a91.1.2024.08.27.20.03.53 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Aug 2024 20:03:59 -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 , Paul Moore , James Morris , "Serge E. Hallyn" , Stephen Smalley , Ondrej Mosnacek Subject: [PATCH v8 3/8] security: Replace memcpy() with get_task_comm() Date: Wed, 28 Aug 2024 11:03:16 +0800 Message-Id: <20240828030321.20688-4-laoar.shao@gmail.com> X-Mailer: git-send-email 2.30.1 (Apple Git-130) In-Reply-To: <20240828030321.20688-1-laoar.shao@gmail.com> References: <20240828030321.20688-1-laoar.shao@gmail.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Quoted from Linus [0]: selinux never wanted a lock, and never wanted any kind of *consistent* result, it just wanted a *stable* result. Using get_task_comm() to read the task comm ensures that the name is always NUL-terminated, regardless of the source string. This approach also facilitates future extensions to the task comm. Signed-off-by: Yafang Shao LINK: https://lore.kernel.org/all/CAHk-=wivfrF0_zvf+oj6==Sh=-npJooP8chLPEfaFV0oNYTTBA@mail.gmail.com/ [0] Acked-by: Paul Moore Cc: James Morris Cc: "Serge E. Hallyn" Cc: Stephen Smalley Cc: Ondrej Mosnacek --- security/lsm_audit.c | 4 ++-- security/selinux/selinuxfs.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/security/lsm_audit.c b/security/lsm_audit.c index 849e832719e2..9a8352972086 100644 --- a/security/lsm_audit.c +++ b/security/lsm_audit.c @@ -207,7 +207,7 @@ static void dump_common_audit_data(struct audit_buffer *ab, BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2); audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current)); - audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm))); + audit_log_untrustedstring(ab, get_task_comm(comm, current)); switch (a->type) { case LSM_AUDIT_DATA_NONE: @@ -302,7 +302,7 @@ static void dump_common_audit_data(struct audit_buffer *ab, char comm[sizeof(tsk->comm)]; audit_log_format(ab, " opid=%d ocomm=", pid); audit_log_untrustedstring(ab, - memcpy(comm, tsk->comm, sizeof(comm))); + get_task_comm(comm, tsk)); } } break; diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index e172f182b65c..c9b05be27ddb 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -708,7 +708,7 @@ static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf, if (new_value) { char comm[sizeof(current->comm)]; - memcpy(comm, current->comm, sizeof(comm)); + strscpy(comm, current->comm); pr_err("SELinux: %s (%d) set checkreqprot to 1. This is no longer supported.\n", comm, current->pid); }