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[198.0.35.241]) by smtp.gmail.com with ESMTPSA id r15-20020a62e40f000000b0065001705ea5sm1232849pfh.193.2023.05.30.16.21.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 May 2023 16:21:16 -0700 (PDT) Date: Tue, 30 May 2023 16:21:15 -0700 From: Kees Cook To: Azeem Shaikh Cc: Maxim Krasnyansky , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, Richard Weinberger , Anton Ivanov , Johannes Berg , linux-um@lists.infradead.org Subject: Re: [PATCH] uml: Replace all non-returning strlcpy with strscpy Message-ID: <202305301621.239F666@keescook> References: <20230530164004.986750-1-azeemshaikh38@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230530164004.986750-1-azeemshaikh38@gmail.com> X-Spam-Status: No, score=-2.3 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 30, 2023 at 04:40:04PM +0000, Azeem Shaikh wrote: > 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 -- Kees Cook