From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 335146FA7 for ; Sun, 17 Sep 2023 19:17:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 911E8C433C7; Sun, 17 Sep 2023 19:17:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694978246; bh=JWs0LBhpwwIUS7LntikmAzFCPNAkZpkFGORHMHIL6Cc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r0sC+M8JtevOTr2ZrScnF50KtAkv6IJpexripD3eIUY8IiU05DRqUvaP8jZfFHP77 AE3Ll2x2JWSHb5WHh+SYU7GHoZ1k3bWUZrSubyPXRGknG/MBbVpLG9rGkCba3Wz7rD APJ3dxpEqZ6qr3ZWRcReH6lSDjmLaKxPpVPB8/OQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christoph Hellwig , Luis Chamberlain Subject: [PATCH 5.10 006/406] modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules Date: Sun, 17 Sep 2023 21:07:40 +0200 Message-ID: <20230917191101.257176910@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191101.035638219@linuxfoundation.org> References: <20230917191101.035638219@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christoph Hellwig commit 9011e49d54dcc7653ebb8a1e05b5badb5ecfa9f9 upstream. It has recently come to my attention that nvidia is circumventing the protection added in 262e6ae7081d ("modules: inherit TAINT_PROPRIETARY_MODULE") by importing exports from their proprietary modules into an allegedly GPL licensed module and then rexporting them. Given that symbol_get was only ever intended for tightly cooperating modules using very internal symbols it is logical to restrict it to being used on EXPORT_SYMBOL_GPL and prevent nvidia from costly DMCA Circumvention of Access Controls law suites. All symbols except for four used through symbol_get were already exported as EXPORT_SYMBOL_GPL, and the remaining four ones were switched over in the preparation patches. Fixes: 262e6ae7081d ("modules: inherit TAINT_PROPRIETARY_MODULE") Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman --- kernel/module.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/kernel/module.c +++ b/kernel/module.c @@ -2268,15 +2268,26 @@ static void free_module(struct module *m void *__symbol_get(const char *symbol) { struct module *owner; + enum mod_license license; const struct kernel_symbol *sym; preempt_disable(); - sym = find_symbol(symbol, &owner, NULL, NULL, true, true); - if (sym && strong_try_module_get(owner)) + sym = find_symbol(symbol, &owner, NULL, &license, true, true); + if (!sym) + goto fail; + if (license != GPL_ONLY) { + pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n", + symbol); + goto fail; + } + if (strong_try_module_get(owner)) sym = NULL; preempt_enable(); return sym ? (void *)kernel_symbol_value(sym) : NULL; +fail: + preempt_enable(); + return NULL; } EXPORT_SYMBOL_GPL(__symbol_get);