From patchwork Tue Jan 11 11:37:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12709754 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD09FC433FE for ; Tue, 11 Jan 2022 11:38:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349580AbiAKLiB (ORCPT ); Tue, 11 Jan 2022 06:38:01 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:33580 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349514AbiAKLh7 (ORCPT ); Tue, 11 Jan 2022 06:37:59 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 0C23B1F3BD; Tue, 11 Jan 2022 11:37:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1641901077; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IrWBD7TI68EgG0wGR5MEbMvcsfaxaq2AlRDdyvro99A=; b=k7WKj6ieTufQqBFIomtdUj8dHTMl66HFPS+wMod8EciFV2Diyy8h2/iM+vzBJfPYYh84bU 4v0LO2o1fKonms79zgVQUjIAA2QMZAS8nIK0oBDXW6crxx7/HCPLhm8K4FR6wsQwEt4jkU 77XNw8GKUIry1x9Z6Jrq+F4laimZnA8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1641901077; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IrWBD7TI68EgG0wGR5MEbMvcsfaxaq2AlRDdyvro99A=; b=qe09BhZxlfhj9FFa9+Xl+y48jwbA0qkP0Pajeo5bbzT0Cm8Zwlx0/2ja82etTw3jZJuNBM bOY9niiLpfvQURCQ== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) by relay2.suse.de (Postfix) with ESMTP id B98EDA3B8D; Tue, 11 Jan 2022 11:37:56 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org Cc: Michal Suchanek , kexec@lists.infradead.org, Philipp Rudo , Mimi Zohar , Nayna , Rob Herring , linux-s390@vger.kernel.org, Vasily Gorbik , Lakshmi Ramasubramanian , Heiko Carstens , Jessica Yu , linux-kernel@vger.kernel.org, David Howells , Christian Borntraeger , Luis Chamberlain , Paul Mackerras , Hari Bathini , Alexander Gordeev , linuxppc-dev@lists.ozlabs.org, Frank van der Linden , Thiago Jung Bauermann , Daniel Axtens , buendgen@de.ibm.com, Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Herbert Xu , "David S. Miller" , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , Sven Schnelle , Baoquan He , linux-security-module@vger.kernel.org Subject: [PATCH v5 1/6] s390/kexec_file: Don't opencode appended signature check. Date: Tue, 11 Jan 2022 12:37:43 +0100 Message-Id: <940cd6a0e88793060cdf5ddb7880c03564b38bdd.1641900831.git.msuchanek@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Module verification already implements appeded signature check. Reuse it for kexec_file. The kexec_file implementation uses EKEYREJECTED error in some cases when there is no key and the common implementation uses ENOPKG or EBADMSG instead. Signed-off-by: Michal Suchanek Acked-by: Heiko Carstens --- v3: Philipp Rudo : Update the commit with note about change of return value --- arch/s390/kernel/machine_kexec_file.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-) diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c index 8f43575a4dd3..c944d71316c7 100644 --- a/arch/s390/kernel/machine_kexec_file.c +++ b/arch/s390/kernel/machine_kexec_file.c @@ -31,6 +31,7 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len) const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1; struct module_signature *ms; unsigned long sig_len; + int ret; /* Skip signature verification when not secure IPLed. */ if (!ipl_secure_flag) @@ -45,25 +46,12 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len) kernel_len -= marker_len; ms = (void *)kernel + kernel_len - sizeof(*ms); - kernel_len -= sizeof(*ms); + ret = mod_check_sig(ms, kernel_len, "kexec"); + if (ret) + return ret; sig_len = be32_to_cpu(ms->sig_len); - if (sig_len >= kernel_len) - return -EKEYREJECTED; - kernel_len -= sig_len; - - if (ms->id_type != PKEY_ID_PKCS7) - return -EKEYREJECTED; - - if (ms->algo != 0 || - ms->hash != 0 || - ms->signer_len != 0 || - ms->key_id_len != 0 || - ms->__pad[0] != 0 || - ms->__pad[1] != 0 || - ms->__pad[2] != 0) { - return -EBADMSG; - } + kernel_len -= sizeof(*ms) + sig_len; return verify_pkcs7_signature(kernel, kernel_len, kernel + kernel_len, sig_len, From patchwork Tue Jan 11 11:37:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12709755 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8B46C433EF for ; Tue, 11 Jan 2022 11:38:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349612AbiAKLiD (ORCPT ); Tue, 11 Jan 2022 06:38:03 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:34534 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349517AbiAKLh7 (ORCPT ); Tue, 11 Jan 2022 06:37:59 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 54830212C5; Tue, 11 Jan 2022 11:37:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1641901077; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4J1Equr5SRHl8sUpAyd5zQDZ43Xlt/8Ec9OMeaSfxcY=; b=LkEFaDSjYtvEJzgiaGuHxPFdE1vr77ZW5l9NYBTED9urrJMxLhzudtg9AvAYiwFmv53a1t qIHI9N9f0xgndaKuFnZD75rbVOJsA+O5joGEe955yjiY3dI0IqOIroEnxJ5z4sDltcxSpm DoN8+gsGY2fk4CdmG0VndVAQTzeZfTQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1641901077; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4J1Equr5SRHl8sUpAyd5zQDZ43Xlt/8Ec9OMeaSfxcY=; b=YRRHgZnsw5ZrPmPES1jjvJdzYMBXK7czudIVeXIi+3ggepCN9lo3K0h4rQmIcGqAvH9Lza yWvgJD+jfAFy4DAw== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) by relay2.suse.de (Postfix) with ESMTP id 0BEC0A3B8E; Tue, 11 Jan 2022 11:37:57 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org Cc: Michal Suchanek , kexec@lists.infradead.org, Philipp Rudo , Mimi Zohar , Nayna , Rob Herring , linux-s390@vger.kernel.org, Vasily Gorbik , Lakshmi Ramasubramanian , Heiko Carstens , Jessica Yu , linux-kernel@vger.kernel.org, David Howells , Christian Borntraeger , Luis Chamberlain , Paul Mackerras , Hari Bathini , Alexander Gordeev , linuxppc-dev@lists.ozlabs.org, Frank van der Linden , Thiago Jung Bauermann , Daniel Axtens , buendgen@de.ibm.com, Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Herbert Xu , "David S. Miller" , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , Sven Schnelle , Baoquan He , linux-security-module@vger.kernel.org Subject: [PATCH v5 2/6] powerpc/kexec_file: Add KEXEC_SIG support. Date: Tue, 11 Jan 2022 12:37:44 +0100 Message-Id: X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Copy the code from s390x Both powerpc and s390x use appended signature format (as opposed to EFI based patforms using PE format). Signed-off-by: Michal Suchanek Acked-by: Michael Ellerman --- v3: - Philipp Rudo : Update the comit message with explanation why the s390 code is usable on powerpc. - Include correct header for mod_check_sig - Nayna : Mention additional IMA features in kconfig text --- arch/powerpc/Kconfig | 16 ++++++++++++++++ arch/powerpc/kexec/elf_64.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index dea74d7717c0..1cde9b6c5987 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -560,6 +560,22 @@ config KEXEC_FILE config ARCH_HAS_KEXEC_PURGATORY def_bool KEXEC_FILE +config KEXEC_SIG + bool "Verify kernel signature during kexec_file_load() syscall" + depends on KEXEC_FILE && MODULE_SIG_FORMAT + help + This option makes kernel signature verification mandatory for + the kexec_file_load() syscall. + + In addition to that option, you need to enable signature + verification for the corresponding kernel image type being + loaded in order for this to work. + + Note: on powerpc IMA_ARCH_POLICY also implements kexec'ed kernel + verification. In addition IMA adds kernel hashes to the measurement + list, extends IMA PCR in the TPM, and implements kernel image + blacklist by hash. + config RELOCATABLE bool "Build a relocatable kernel" depends on PPC64 || (FLATMEM && (44x || FSL_BOOKE)) diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index eeb258002d1e..98d1cb5135b4 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -23,6 +23,7 @@ #include #include #include +#include static void *elf64_load(struct kimage *image, char *kernel_buf, unsigned long kernel_len, char *initrd, @@ -151,7 +152,42 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, return ret ? ERR_PTR(ret) : NULL; } +#ifdef CONFIG_KEXEC_SIG +int elf64_verify_sig(const char *kernel, unsigned long kernel_len) +{ + const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1; + struct module_signature *ms; + unsigned long sig_len; + int ret; + + if (marker_len > kernel_len) + return -EKEYREJECTED; + + if (memcmp(kernel + kernel_len - marker_len, MODULE_SIG_STRING, + marker_len)) + return -EKEYREJECTED; + kernel_len -= marker_len; + + ms = (void *)kernel + kernel_len - sizeof(*ms); + ret = mod_check_sig(ms, kernel_len, "kexec"); + if (ret) + return ret; + + sig_len = be32_to_cpu(ms->sig_len); + kernel_len -= sizeof(*ms) + sig_len; + + return verify_pkcs7_signature(kernel, kernel_len, + kernel + kernel_len, sig_len, + VERIFY_USE_PLATFORM_KEYRING, + VERIFYING_MODULE_SIGNATURE, + NULL, NULL); +} +#endif /* CONFIG_KEXEC_SIG */ + const struct kexec_file_ops kexec_elf64_ops = { .probe = kexec_elf_probe, .load = elf64_load, +#ifdef CONFIG_KEXEC_SIG + .verify_sig = elf64_verify_sig, +#endif }; From patchwork Tue Jan 11 11:37:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12709759 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B4FEC4332F for ; Tue, 11 Jan 2022 11:38:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349595AbiAKLiC (ORCPT ); Tue, 11 Jan 2022 06:38:02 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:33626 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349546AbiAKLh7 (ORCPT ); Tue, 11 Jan 2022 06:37:59 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 9ACCA1F3BE; Tue, 11 Jan 2022 11:37:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1641901077; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=E5S+PDIMt0cv778Ug4dTHgOhwSV6I7mLY7fYsPSMbc8=; b=cNTa4UdEI8NMT2ulyV45F/C/V13CVcxnHg2/esmZQ9mIhQ4wW8tFjineNtW9R8OYNjpyzQ /zlZ9M4CizPX6Da//4DbLf1GFhpmIzRgQqK8WzvxT/I3jGEGk7/mfQepNvv2M1J7zCxtl2 fc3gS9gTAYfCRnrha03OmoNgg3j/HZY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1641901077; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=E5S+PDIMt0cv778Ug4dTHgOhwSV6I7mLY7fYsPSMbc8=; b=Gx/naHnidUOgdbPPRqig0Wgs+UDBOAiZnhMMzrD37EGj9I3JOKbn2QGeVXTk7DLgO/rsjU BxTzShMlokMLUABA== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) by relay2.suse.de (Postfix) with ESMTP id 5459AA3B8F; Tue, 11 Jan 2022 11:37:57 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org Cc: Michal Suchanek , kexec@lists.infradead.org, Philipp Rudo , Mimi Zohar , Nayna , Rob Herring , linux-s390@vger.kernel.org, Vasily Gorbik , Lakshmi Ramasubramanian , Heiko Carstens , Jessica Yu , linux-kernel@vger.kernel.org, David Howells , Christian Borntraeger , Luis Chamberlain , Paul Mackerras , Hari Bathini , Alexander Gordeev , linuxppc-dev@lists.ozlabs.org, Frank van der Linden , Thiago Jung Bauermann , Daniel Axtens , buendgen@de.ibm.com, Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Herbert Xu , "David S. Miller" , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , Sven Schnelle , Baoquan He , linux-security-module@vger.kernel.org Subject: [PATCH v5 3/6] kexec_file: Don't opencode appended signature verification. Date: Tue, 11 Jan 2022 12:37:45 +0100 Message-Id: <7834eb187ef67cd88fc67f10e831130e3717d776.1641900831.git.msuchanek@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Module verification already implements appeded signature verification. Reuse it for kexec_file. Signed-off-by: Michal Suchanek Reviewed-by: Luis Chamberlain --- v3: - Philipp Rudo : Update the dependency on MODULE_SIG_FORMAT to MODULE_SIG - Include linux/verification.h - previously added in earlier patch v4: - kernel test robot : Use unsigned long rather than size_t for data length - Update the code in kernel/module_signing.c to use pointer rather than memcpy as the kexec and IMA code does --- arch/powerpc/Kconfig | 2 +- arch/powerpc/kexec/elf_64.c | 19 +++------------ arch/s390/Kconfig | 2 +- arch/s390/kernel/machine_kexec_file.c | 18 ++------------ include/linux/verification.h | 3 +++ kernel/module-internal.h | 2 -- kernel/module.c | 4 +++- kernel/module_signing.c | 34 ++++++++++++++++----------- 8 files changed, 33 insertions(+), 51 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 1cde9b6c5987..4092187474ff 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -562,7 +562,7 @@ config ARCH_HAS_KEXEC_PURGATORY config KEXEC_SIG bool "Verify kernel signature during kexec_file_load() syscall" - depends on KEXEC_FILE && MODULE_SIG_FORMAT + depends on KEXEC_FILE && MODULE_SIG help This option makes kernel signature verification mandatory for the kexec_file_load() syscall. diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index 98d1cb5135b4..64cd314cce0d 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -23,6 +23,7 @@ #include #include #include +#include #include static void *elf64_load(struct kimage *image, char *kernel_buf, @@ -156,9 +157,6 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, int elf64_verify_sig(const char *kernel, unsigned long kernel_len) { const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1; - struct module_signature *ms; - unsigned long sig_len; - int ret; if (marker_len > kernel_len) return -EKEYREJECTED; @@ -168,19 +166,8 @@ int elf64_verify_sig(const char *kernel, unsigned long kernel_len) return -EKEYREJECTED; kernel_len -= marker_len; - ms = (void *)kernel + kernel_len - sizeof(*ms); - ret = mod_check_sig(ms, kernel_len, "kexec"); - if (ret) - return ret; - - sig_len = be32_to_cpu(ms->sig_len); - kernel_len -= sizeof(*ms) + sig_len; - - return verify_pkcs7_signature(kernel, kernel_len, - kernel + kernel_len, sig_len, - VERIFY_USE_PLATFORM_KEYRING, - VERIFYING_MODULE_SIGNATURE, - NULL, NULL); + return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, + "kexec_file"); } #endif /* CONFIG_KEXEC_SIG */ diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 2a5bb4f29cfe..cece7152ea35 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -544,7 +544,7 @@ config ARCH_HAS_KEXEC_PURGATORY config KEXEC_SIG bool "Verify kernel signature during kexec_file_load() syscall" - depends on KEXEC_FILE && MODULE_SIG_FORMAT + depends on KEXEC_FILE && MODULE_SIG help This option makes kernel signature verification mandatory for the kexec_file_load() syscall. diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c index c944d71316c7..345f2eab6e04 100644 --- a/arch/s390/kernel/machine_kexec_file.c +++ b/arch/s390/kernel/machine_kexec_file.c @@ -29,9 +29,6 @@ const struct kexec_file_ops * const kexec_file_loaders[] = { int s390_verify_sig(const char *kernel, unsigned long kernel_len) { const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1; - struct module_signature *ms; - unsigned long sig_len; - int ret; /* Skip signature verification when not secure IPLed. */ if (!ipl_secure_flag) @@ -45,19 +42,8 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len) return -EKEYREJECTED; kernel_len -= marker_len; - ms = (void *)kernel + kernel_len - sizeof(*ms); - ret = mod_check_sig(ms, kernel_len, "kexec"); - if (ret) - return ret; - - sig_len = be32_to_cpu(ms->sig_len); - kernel_len -= sizeof(*ms) + sig_len; - - return verify_pkcs7_signature(kernel, kernel_len, - kernel + kernel_len, sig_len, - VERIFY_USE_PLATFORM_KEYRING, - VERIFYING_MODULE_SIGNATURE, - NULL, NULL); + return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, + "kexec_file"); } #endif /* CONFIG_KEXEC_SIG */ diff --git a/include/linux/verification.h b/include/linux/verification.h index a655923335ae..32db9287a7b0 100644 --- a/include/linux/verification.h +++ b/include/linux/verification.h @@ -60,5 +60,8 @@ extern int verify_pefile_signature(const void *pebuf, unsigned pelen, enum key_being_used_for usage); #endif +int verify_appended_signature(const void *data, unsigned long *len, + struct key *trusted_keys, const char *what); + #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ #endif /* _LINUX_VERIFY_PEFILE_H */ diff --git a/kernel/module-internal.h b/kernel/module-internal.h index 33783abc377b..80461e14bf29 100644 --- a/kernel/module-internal.h +++ b/kernel/module-internal.h @@ -27,5 +27,3 @@ struct load_info { unsigned int sym, str, mod, vers, info, pcpu; } index; }; - -extern int mod_verify_sig(const void *mod, struct load_info *info); diff --git a/kernel/module.c b/kernel/module.c index 84a9141a5e15..8481933dfa92 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -57,6 +57,7 @@ #include #include #include +#include #include #include "module-internal.h" @@ -2894,7 +2895,8 @@ static int module_sig_check(struct load_info *info, int flags) memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { /* We truncate the module to discard the signature */ info->len -= markerlen; - err = mod_verify_sig(mod, info); + err = verify_appended_signature(mod, &info->len, + VERIFY_USE_SECONDARY_KEYRING, "module"); if (!err) { info->sig_ok = true; return 0; diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 8723ae70ea1f..30149969f21f 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -14,32 +14,38 @@ #include #include "module-internal.h" -/* - * Verify the signature on a module. +/** + * verify_appended_signature - Verify the signature on a module with the + * signature marker stripped. + * @data: The data to be verified + * @len: Size of @data. + * @trusted_keys: Keyring to use for verification + * @what: Informational string for log messages */ -int mod_verify_sig(const void *mod, struct load_info *info) +int verify_appended_signature(const void *data, unsigned long *len, + struct key *trusted_keys, const char *what) { - struct module_signature ms; - size_t sig_len, modlen = info->len; + struct module_signature *ms; + unsigned long sig_len, modlen = *len; int ret; - pr_devel("==>%s(,%zu)\n", __func__, modlen); + pr_devel("==>%s(,%lu)\n", __func__, modlen); - if (modlen <= sizeof(ms)) + if (modlen <= sizeof(*ms)) return -EBADMSG; - memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms)); + ms = data + modlen - sizeof(*ms); - ret = mod_check_sig(&ms, modlen, "module"); + ret = mod_check_sig(ms, modlen, what); if (ret) return ret; - sig_len = be32_to_cpu(ms.sig_len); - modlen -= sig_len + sizeof(ms); - info->len = modlen; + sig_len = be32_to_cpu(ms->sig_len); + modlen -= sig_len + sizeof(*ms); + *len = modlen; - return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len, - VERIFY_USE_SECONDARY_KEYRING, + return verify_pkcs7_signature(data, modlen, data + modlen, sig_len, + trusted_keys, VERIFYING_MODULE_SIGNATURE, NULL, NULL); } From patchwork Tue Jan 11 11:37:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12709756 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E0EEC4321E for ; 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a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1641901077; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9Sg8NmS9Cl8uGlravuAR0TWOLfnwUgnMmpUpTIKU9d8=; b=vMq8zMm62k4dH5aGzsUbtvmqfiDQMe811JVuN7Nqu7LtZTfJe1uUyAWVdPTZ/+8d0tyVIJ x0Hvv8PGNjZbhcAw== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) by relay2.suse.de (Postfix) with ESMTP id 9B859A3B90; Tue, 11 Jan 2022 11:37:57 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org Cc: Michal Suchanek , kexec@lists.infradead.org, Philipp Rudo , Mimi Zohar , Nayna , Rob Herring , linux-s390@vger.kernel.org, Vasily Gorbik , Lakshmi Ramasubramanian , Heiko Carstens , Jessica Yu , linux-kernel@vger.kernel.org, David Howells , Christian Borntraeger , Luis Chamberlain , Paul Mackerras , Hari Bathini , Alexander Gordeev , linuxppc-dev@lists.ozlabs.org, Frank van der Linden , Thiago Jung Bauermann , Daniel Axtens , buendgen@de.ibm.com, Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Herbert Xu , "David S. Miller" , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , Sven Schnelle , Baoquan He , linux-security-module@vger.kernel.org Subject: [PATCH v5 4/6] module: strip the signature marker in the verification function. Date: Tue, 11 Jan 2022 12:37:46 +0100 Message-Id: <96d29773b9ef418a71b1d8bbfd0a456a0f996ec6.1641900831.git.msuchanek@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org It is stripped by each caller separately. Note: this changes the error for kexec_file from EKEYREJECTED to ENODATA when the signature marker is missing. Signed-off-by: Michal Suchanek Reviewed-by: Luis Chamberlain --- v3: - Philipp Rudo : Update the commit with note about change of raturn value - the module_signature.h is now no longer needed for kexec_file --- arch/powerpc/kexec/elf_64.c | 11 ----------- arch/s390/kernel/machine_kexec_file.c | 11 ----------- kernel/module.c | 7 +------ kernel/module_signing.c | 12 ++++++++++-- 4 files changed, 11 insertions(+), 30 deletions(-) diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index 64cd314cce0d..6dec8151ef73 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -24,7 +24,6 @@ #include #include #include -#include static void *elf64_load(struct kimage *image, char *kernel_buf, unsigned long kernel_len, char *initrd, @@ -156,16 +155,6 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, #ifdef CONFIG_KEXEC_SIG int elf64_verify_sig(const char *kernel, unsigned long kernel_len) { - const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1; - - if (marker_len > kernel_len) - return -EKEYREJECTED; - - if (memcmp(kernel + kernel_len - marker_len, MODULE_SIG_STRING, - marker_len)) - return -EKEYREJECTED; - kernel_len -= marker_len; - return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, "kexec_file"); } diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c index 345f2eab6e04..c3deccf1da83 100644 --- a/arch/s390/kernel/machine_kexec_file.c +++ b/arch/s390/kernel/machine_kexec_file.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include #include @@ -28,20 +27,10 @@ const struct kexec_file_ops * const kexec_file_loaders[] = { #ifdef CONFIG_KEXEC_SIG int s390_verify_sig(const char *kernel, unsigned long kernel_len) { - const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1; - /* Skip signature verification when not secure IPLed. */ if (!ipl_secure_flag) return 0; - if (marker_len > kernel_len) - return -EKEYREJECTED; - - if (memcmp(kernel + kernel_len - marker_len, MODULE_SIG_STRING, - marker_len)) - return -EKEYREJECTED; - kernel_len -= marker_len; - return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, "kexec_file"); } diff --git a/kernel/module.c b/kernel/module.c index 8481933dfa92..d91ca0f93a40 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2882,7 +2882,6 @@ static inline void kmemleak_load_module(const struct module *mod, static int module_sig_check(struct load_info *info, int flags) { int err = -ENODATA; - const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; const char *reason; const void *mod = info->hdr; @@ -2890,11 +2889,7 @@ static int module_sig_check(struct load_info *info, int flags) * Require flags == 0, as a module with version information * removed is no longer the module that was signed */ - if (flags == 0 && - info->len > markerlen && - memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { - /* We truncate the module to discard the signature */ - info->len -= markerlen; + if (flags == 0) { err = verify_appended_signature(mod, &info->len, VERIFY_USE_SECONDARY_KEYRING, "module"); if (!err) { diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 30149969f21f..39a6dd7c6dd2 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -15,8 +15,7 @@ #include "module-internal.h" /** - * verify_appended_signature - Verify the signature on a module with the - * signature marker stripped. + * verify_appended_signature - Verify the signature on a module * @data: The data to be verified * @len: Size of @data. * @trusted_keys: Keyring to use for verification @@ -25,12 +24,21 @@ int verify_appended_signature(const void *data, unsigned long *len, struct key *trusted_keys, const char *what) { + const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; struct module_signature *ms; unsigned long sig_len, modlen = *len; int ret; pr_devel("==>%s(,%lu)\n", __func__, modlen); + if (markerlen > modlen) + return -ENODATA; + + if (memcmp(data + modlen - markerlen, MODULE_SIG_STRING, + markerlen)) + return -ENODATA; + modlen -= markerlen; + if (modlen <= sizeof(*ms)) return -EBADMSG; From patchwork Tue Jan 11 11:37:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12709757 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A502AC433F5 for ; Tue, 11 Jan 2022 11:38:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349648AbiAKLiF (ORCPT ); Tue, 11 Jan 2022 06:38:05 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:33672 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349563AbiAKLiA (ORCPT ); Tue, 11 Jan 2022 06:38:00 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 3ABB91F3BF; Tue, 11 Jan 2022 11:37:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; 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Tue, 11 Jan 2022 11:37:57 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org Cc: Michal Suchanek , kexec@lists.infradead.org, Philipp Rudo , Mimi Zohar , Nayna , Rob Herring , linux-s390@vger.kernel.org, Vasily Gorbik , Lakshmi Ramasubramanian , Heiko Carstens , Jessica Yu , linux-kernel@vger.kernel.org, David Howells , Christian Borntraeger , Luis Chamberlain , Paul Mackerras , Hari Bathini , Alexander Gordeev , linuxppc-dev@lists.ozlabs.org, Frank van der Linden , Thiago Jung Bauermann , Daniel Axtens , buendgen@de.ibm.com, Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Herbert Xu , "David S. Miller" , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , Sven Schnelle , Baoquan He , linux-security-module@vger.kernel.org Subject: [PATCH v5 5/6] module: Use key_being_used_for for log messages in verify_appended_signature Date: Tue, 11 Jan 2022 12:37:47 +0100 Message-Id: <65d9913441b16e27b672cfabbab24fa5c12bee14.1641900831.git.msuchanek@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Add value for kexec appended signature and pass in key_being_used_for enum rather than a string to verify_appended_signature to produce log messages about the signature. Signed-off-by: Michal Suchanek Acked-by: Luis Chamberlain --- arch/powerpc/kexec/elf_64.c | 2 +- arch/s390/kernel/machine_kexec_file.c | 2 +- crypto/asymmetric_keys/asymmetric_type.c | 1 + include/linux/verification.h | 4 +++- kernel/module.c | 3 ++- kernel/module_signing.c | 11 ++++++----- 6 files changed, 14 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index 6dec8151ef73..c50869195d51 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -156,7 +156,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, int elf64_verify_sig(const char *kernel, unsigned long kernel_len) { return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, - "kexec_file"); + VERIFYING_KEXEC_APPENDED_SIGNATURE); } #endif /* CONFIG_KEXEC_SIG */ diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c index c3deccf1da83..63eec38e3137 100644 --- a/arch/s390/kernel/machine_kexec_file.c +++ b/arch/s390/kernel/machine_kexec_file.c @@ -32,7 +32,7 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len) return 0; return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, - "kexec_file"); + VERIFYING_KEXEC_APPENDED_SIGNATURE); } #endif /* CONFIG_KEXEC_SIG */ diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index ad8af3d70ac0..6fd20eec3882 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -25,6 +25,7 @@ const char *const key_being_used_for[NR__KEY_BEING_USED_FOR] = { [VERIFYING_KEXEC_PE_SIGNATURE] = "kexec PE sig", [VERIFYING_KEY_SIGNATURE] = "key sig", [VERIFYING_KEY_SELF_SIGNATURE] = "key self sig", + [VERIFYING_KEXEC_APPENDED_SIGNATURE] = "kexec appended sig", [VERIFYING_UNSPECIFIED_SIGNATURE] = "unspec sig", }; EXPORT_SYMBOL_GPL(key_being_used_for); diff --git a/include/linux/verification.h b/include/linux/verification.h index 32db9287a7b0..f92c49443b4f 100644 --- a/include/linux/verification.h +++ b/include/linux/verification.h @@ -26,6 +26,7 @@ enum key_being_used_for { VERIFYING_KEXEC_PE_SIGNATURE, VERIFYING_KEY_SIGNATURE, VERIFYING_KEY_SELF_SIGNATURE, + VERIFYING_KEXEC_APPENDED_SIGNATURE, VERIFYING_UNSPECIFIED_SIGNATURE, NR__KEY_BEING_USED_FOR }; @@ -61,7 +62,8 @@ extern int verify_pefile_signature(const void *pebuf, unsigned pelen, #endif int verify_appended_signature(const void *data, unsigned long *len, - struct key *trusted_keys, const char *what); + struct key *trusted_keys, + enum key_being_used_for purpose); #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ #endif /* _LINUX_VERIFY_PEFILE_H */ diff --git a/kernel/module.c b/kernel/module.c index d91ca0f93a40..0a359dc6b690 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2891,7 +2891,8 @@ static int module_sig_check(struct load_info *info, int flags) */ if (flags == 0) { err = verify_appended_signature(mod, &info->len, - VERIFY_USE_SECONDARY_KEYRING, "module"); + VERIFY_USE_SECONDARY_KEYRING, + VERIFYING_MODULE_SIGNATURE); if (!err) { info->sig_ok = true; return 0; diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 39a6dd7c6dd2..20857d2a15ca 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -19,17 +19,18 @@ * @data: The data to be verified * @len: Size of @data. * @trusted_keys: Keyring to use for verification - * @what: Informational string for log messages + * @purpose: The use to which the key is being put */ int verify_appended_signature(const void *data, unsigned long *len, - struct key *trusted_keys, const char *what) + struct key *trusted_keys, + enum key_being_used_for purpose) { const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; struct module_signature *ms; unsigned long sig_len, modlen = *len; int ret; - pr_devel("==>%s(,%lu)\n", __func__, modlen); + pr_devel("==>%s %s(,%lu)\n", __func__, key_being_used_for[purpose], modlen); if (markerlen > modlen) return -ENODATA; @@ -44,7 +45,7 @@ int verify_appended_signature(const void *data, unsigned long *len, ms = data + modlen - sizeof(*ms); - ret = mod_check_sig(ms, modlen, what); + ret = mod_check_sig(ms, modlen, key_being_used_for[purpose]); if (ret) return ret; @@ -54,6 +55,6 @@ int verify_appended_signature(const void *data, unsigned long *len, return verify_pkcs7_signature(data, modlen, data + modlen, sig_len, trusted_keys, - VERIFYING_MODULE_SIGNATURE, + purpose, NULL, NULL); } From patchwork Tue Jan 11 11:37:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12709758 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6FFC6C4321E for ; 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a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1641901078; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Nnudm31TWLhKvg8iKBvA1bfNToyh2dvEbi+Aqj3JOf0=; b=fAw0JhWNwop5nDbpxOR5hDu1JdKpGwH7AXDTV128GOp5d8eA8ZaWvQxIzuH9ztG3pbiEh0 VT07iLtEGTaYHwAA== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) by relay2.suse.de (Postfix) with ESMTP id 3A301A3B92; Tue, 11 Jan 2022 11:37:58 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org Cc: Michal Suchanek , kexec@lists.infradead.org, Philipp Rudo , Mimi Zohar , Nayna , Rob Herring , linux-s390@vger.kernel.org, Vasily Gorbik , Lakshmi Ramasubramanian , Heiko Carstens , Jessica Yu , linux-kernel@vger.kernel.org, David Howells , Christian Borntraeger , Luis Chamberlain , Paul Mackerras , Hari Bathini , Alexander Gordeev , linuxppc-dev@lists.ozlabs.org, Frank van der Linden , Thiago Jung Bauermann , Daniel Axtens , buendgen@de.ibm.com, Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Herbert Xu , "David S. Miller" , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , Sven Schnelle , Baoquan He , linux-security-module@vger.kernel.org Subject: [PATCH v5 6/6] module: Move duplicate mod_check_sig users code to mod_parse_sig Date: Tue, 11 Jan 2022 12:37:48 +0100 Message-Id: <687db74a714d50b9c83d7ac024da4f7dec0d9a1d.1641900831.git.msuchanek@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Multiple users of mod_check_sig check for the marker, then call mod_check_sig, extract signature length, and remove the signature. Put this code in one place together with mod_check_sig. This changes the error from ENOENT to ENODATA for ima_read_modsig in the case the signature marker is missing. This also changes the buffer length in ima_read_modsig from size_t to unsigned long. This reduces the possible value range on 32bit but the length refers to kernel in-memory buffer which cannot be longer than ULONG_MAX. Also change mod_check_sig to unsigned long while at it. Signed-off-by: Michal Suchanek Reviewed-by: Luis Chamberlain --- v3: - Philipp Rudo : Update the commit with note about change of raturn value - Preserve the EBADMSG error code while moving code araound v4: - remove unused variable ms in module_signing.c - note about buffer length v5: - also change the functions in module_signature.c to unsigned long --- include/linux/module_signature.h | 4 +- kernel/module_signature.c | 58 ++++++++++++++++++++++++++++- kernel/module_signing.c | 27 ++------------ security/integrity/ima/ima_modsig.c | 22 ++--------- 4 files changed, 66 insertions(+), 45 deletions(-) diff --git a/include/linux/module_signature.h b/include/linux/module_signature.h index 7eb4b00381ac..e5fb157c085c 100644 --- a/include/linux/module_signature.h +++ b/include/linux/module_signature.h @@ -40,7 +40,9 @@ struct module_signature { __be32 sig_len; /* Length of signature data */ }; -int mod_check_sig(const struct module_signature *ms, size_t file_len, +int mod_check_sig(const struct module_signature *ms, unsigned long file_len, + const char *name); +int mod_parse_sig(const void *data, unsigned long *len, unsigned long *sig_len, const char *name); #endif /* _LINUX_MODULE_SIGNATURE_H */ diff --git a/kernel/module_signature.c b/kernel/module_signature.c index 00132d12487c..4a36405ecd08 100644 --- a/kernel/module_signature.c +++ b/kernel/module_signature.c @@ -8,17 +8,39 @@ #include #include +#include #include #include +/** + * mod_check_sig_marker - check that the given data has signature marker at the end + * + * @data: Data with appended signature + * @len: Length of data. Signature marker length is subtracted on success. + */ +static inline int mod_check_sig_marker(const void *data, unsigned long *len) +{ + const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; + + if (markerlen > *len) + return -ENODATA; + + if (memcmp(data + *len - markerlen, MODULE_SIG_STRING, + markerlen)) + return -ENODATA; + + *len -= markerlen; + return 0; +} + /** * mod_check_sig - check that the given signature is sane * * @ms: Signature to check. - * @file_len: Size of the file to which @ms is appended. + * @file_len: Size of the file to which @ms is appended (without the marker). * @name: What is being checked. Used for error messages. */ -int mod_check_sig(const struct module_signature *ms, size_t file_len, +int mod_check_sig(const struct module_signature *ms, unsigned long file_len, const char *name) { if (be32_to_cpu(ms->sig_len) >= file_len - sizeof(*ms)) @@ -44,3 +66,35 @@ int mod_check_sig(const struct module_signature *ms, size_t file_len, return 0; } + +/** + * mod_parse_sig - check that the given signature is sane and determine signature length + * + * @data: Data with appended signature. + * @len: Length of data. Signature and marker length is subtracted on success. + * @sig_len: Length of signature. Filled on success. + * @name: What is being checked. Used for error messages. + */ +int mod_parse_sig(const void *data, unsigned long *len, unsigned long *sig_len, const char *name) +{ + const struct module_signature *sig; + int rc; + + rc = mod_check_sig_marker(data, len); + if (rc) + return rc; + + if (*len < sizeof(*sig)) + return -EBADMSG; + + sig = data + (*len - sizeof(*sig)); + + rc = mod_check_sig(sig, *len, name); + if (rc) + return rc; + + *sig_len = be32_to_cpu(sig->sig_len); + *len -= *sig_len + sizeof(*sig); + + return 0; +} diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 20857d2a15ca..1d4cb03cce21 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -25,35 +25,16 @@ int verify_appended_signature(const void *data, unsigned long *len, struct key *trusted_keys, enum key_being_used_for purpose) { - const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; - struct module_signature *ms; - unsigned long sig_len, modlen = *len; + unsigned long sig_len; int ret; - pr_devel("==>%s %s(,%lu)\n", __func__, key_being_used_for[purpose], modlen); + pr_devel("==>%s %s(,%lu)\n", __func__, key_being_used_for[purpose], *len); - if (markerlen > modlen) - return -ENODATA; - - if (memcmp(data + modlen - markerlen, MODULE_SIG_STRING, - markerlen)) - return -ENODATA; - modlen -= markerlen; - - if (modlen <= sizeof(*ms)) - return -EBADMSG; - - ms = data + modlen - sizeof(*ms); - - ret = mod_check_sig(ms, modlen, key_being_used_for[purpose]); + ret = mod_parse_sig(data, len, &sig_len, key_being_used_for[purpose]); if (ret) return ret; - sig_len = be32_to_cpu(ms->sig_len); - modlen -= sig_len + sizeof(*ms); - *len = modlen; - - return verify_pkcs7_signature(data, modlen, data + modlen, sig_len, + return verify_pkcs7_signature(data, *len, data + *len, sig_len, trusted_keys, purpose, NULL, NULL); diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c index fb25723c65bc..b40c8fdf6139 100644 --- a/security/integrity/ima/ima_modsig.c +++ b/security/integrity/ima/ima_modsig.c @@ -37,33 +37,17 @@ struct modsig { * * Return: 0 on success, error code otherwise. */ -int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, +int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t len, struct modsig **modsig) { - const size_t marker_len = strlen(MODULE_SIG_STRING); - const struct module_signature *sig; struct modsig *hdr; - size_t sig_len; - const void *p; + unsigned long sig_len, buf_len = len; int rc; - if (buf_len <= marker_len + sizeof(*sig)) - return -ENOENT; - - p = buf + buf_len - marker_len; - if (memcmp(p, MODULE_SIG_STRING, marker_len)) - return -ENOENT; - - buf_len -= marker_len; - sig = (const struct module_signature *)(p - sizeof(*sig)); - - rc = mod_check_sig(sig, buf_len, func_tokens[func]); + rc = mod_parse_sig(buf, &buf_len, &sig_len, func_tokens[func]); if (rc) return rc; - sig_len = be32_to_cpu(sig->sig_len); - buf_len -= sig_len + sizeof(*sig); - /* Allocate sig_len additional bytes to hold the raw PKCS#7 data. */ hdr = kzalloc(sizeof(*hdr) + sig_len, GFP_KERNEL); if (!hdr)