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[35.188.70.54]) by smtp.gmail.com with ESMTPSA id r5-20020a056638100500b0042319c38763sm6627058jab.15.2023.07.03.09.58.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Jul 2023 09:58:39 -0700 (PDT) From: Azeem Shaikh To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo Cc: linux-hardening@vger.kernel.org, Azeem Shaikh , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] perf: Replace strlcpy with strscpy Date: Mon, 3 Jul 2023 16:58:16 +0000 Message-ID: <20230703165817.2840457-1-azeemshaikh38@gmail.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh Reviewed-by: Kees Cook --- kernel/events/core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 78ae7b6f90fd..2554f5fc70dc 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8249,7 +8249,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event) unsigned int size; memset(comm, 0, sizeof(comm)); - strlcpy(comm, comm_event->task->comm, sizeof(comm)); + strscpy(comm, comm_event->task->comm, sizeof(comm)); size = ALIGN(strlen(comm)+1, sizeof(u64)); comm_event->comm = comm; @@ -8704,7 +8704,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) } cpy_name: - strlcpy(tmp, name, sizeof(tmp)); + strscpy(tmp, name, sizeof(tmp)); name = tmp; got_name: /* @@ -9128,7 +9128,7 @@ void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len, bool unregister, ksym_type == PERF_RECORD_KSYMBOL_TYPE_UNKNOWN) goto err; - strlcpy(name, sym, KSYM_NAME_LEN); + strscpy(name, sym, KSYM_NAME_LEN); name_len = strlen(name) + 1; while (!IS_ALIGNED(name_len, sizeof(u64))) name[name_len++] = '\0';