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[35.188.70.54]) by smtp.gmail.com with ESMTPSA id p10-20020a92c10a000000b0033b27117120sm4090039ile.13.2023.06.13.17.12.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Jun 2023 17:12:48 -0700 (PDT) From: Azeem Shaikh To: Chuck Lever , Jeff Layton , Kees Cook Cc: linux-hardening@vger.kernel.org, Azeem Shaikh , Neil Brown , Olga Kornievskaia , Dai Ngo , Tom Talpey , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, Trond Myklebust , Anna Schumaker , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org Subject: [PATCH v2] SUNRPC: Remove strlcpy Date: Wed, 14 Jun 2023 00:12:46 +0000 Message-ID: <20230614001246.538643-1-azeemshaikh38@gmail.com> X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-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 sysfs_emit(). Direct replacement is safe here since the getter in kernel_params_ops handles -errno return [3]. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 [3] https://elixir.bootlin.com/linux/v6.4-rc6/source/include/linux/moduleparam.h#L52 Signed-off-by: Azeem Shaikh --- net/sunrpc/svc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index e6d4cec61e47..77326f163801 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -109,13 +109,13 @@ param_get_pool_mode(char *buf, const struct kernel_param *kp) switch (*ip) { case SVC_POOL_AUTO: - return strlcpy(buf, "auto\n", 20); + return sysfs_emit(buf, "auto\n"); case SVC_POOL_GLOBAL: - return strlcpy(buf, "global\n", 20); + return sysfs_emit(buf, "global\n"); case SVC_POOL_PERCPU: - return strlcpy(buf, "percpu\n", 20); + return sysfs_emit(buf, "percpu\n"); case SVC_POOL_PERNODE: - return strlcpy(buf, "pernode\n", 20); + return sysfs_emit(buf, "pernode\n"); default: return sprintf(buf, "%d\n", *ip); }