From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pj1-x1042.google.com ([2607:f8b0:4864:20::1042]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jwUOE-0005qa-5j for kexec@lists.infradead.org; Fri, 17 Jul 2020 17:43:20 +0000 Received: by mail-pj1-x1042.google.com with SMTP id b92so6752790pjc.4 for ; Fri, 17 Jul 2020 10:43:16 -0700 (PDT) From: Kees Cook Subject: [PATCH 01/13] firmware_loader: EFI firmware loader must handle pre-allocated buffer Date: Fri, 17 Jul 2020 10:42:56 -0700 Message-Id: <20200717174309.1164575-2-keescook@chromium.org> In-Reply-To: <20200717174309.1164575-1-keescook@chromium.org> References: <20200717174309.1164575-1-keescook@chromium.org> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Scott Branden Cc: "Rafael J. Wysocki" , Peter Zijlstra , Stephen Boyd , Mimi Zohar , David Howells , Peter Jones , "Joel Fernandes (Google)" , linux-security-module@vger.kernel.org, Paul Moore , Mauro Carvalho Chehab , Matthew Garrett , James Morris , Matthew Wilcox , KP Singh , "Serge E. Hallyn" , Kees Cook , selinux@vger.kernel.org, Jessica Yu , Hans de Goede , Alexander Viro , linux-integrity@vger.kernel.org, Greg Kroah-Hartman , Stephen Smalley , Randy Dunlap , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Luis Chamberlain , "Eric W. Biederman" , Dave Olsthoorn , Dmitry Kasatkin , Casey Schaufler , linux-fsdevel@vger.kernel.org, Andrew Morton The EFI platform firmware fallback would clobber any pre-allocated buffers. Instead, correctly refuse to reallocate when too small (as already done in the sysfs fallback), or perform allocation normally when needed. Fixes: e4c2c0ff00ec ("firmware: Add new platform fallback mechanism and firm ware_request_platform()") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook --- To aid in backporting, this change is made before moving kernel_read_file() to separate header/source files. --- drivers/base/firmware_loader/fallback_platform.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c index cdd2c9a9f38a..685edb7dd05a 100644 --- a/drivers/base/firmware_loader/fallback_platform.c +++ b/drivers/base/firmware_loader/fallback_platform.c @@ -25,7 +25,10 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags) if (rc) return rc; /* rc == -ENOENT when the fw was not found */ - fw_priv->data = vmalloc(size); + if (fw_priv->data && size > fw_priv->allocated_size) + return -ENOMEM; + if (!fw_priv->data) + fw_priv->data = vmalloc(size); if (!fw_priv->data) return -ENOMEM; -- 2.25.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec