* Re: [PATCH v4 1/6] x86/ima: define arch_ima_get_secureboot [not found] ` <20180926122210.14642-2-nayna@linux.vnet.ibm.com> @ 2018-09-27 11:33 ` Mimi Zohar 0 siblings, 0 replies; 2+ messages in thread From: Mimi Zohar @ 2018-09-27 11:33 UTC (permalink / raw) To: Nayna Jain, linux-integrity Cc: linux-efi, kexec, linux-kernel, dhowells, Seth Forshee, linux-security-module, jforbes [Cc'ing the kexec mailing list, and Seth] On Wed, 2018-09-26 at 17:52 +0530, Nayna Jain wrote: > Distros are concerned about totally disabling the kexec_load syscall. > As a compromise, the kexec_load syscall will only be disabled when > CONFIG_KEXEC_VERIFY_SIG is configured and the system is booted with > secureboot enabled. > > This patch defines the new arch specific function called > arch_ima_get_secureboot() to retrieve the secureboot state of the system. > > Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com> > Suggested-by: Seth Forshee <seth.forshee@canonical.com> Nice! Mimi > --- > arch/x86/kernel/Makefile | 2 ++ > arch/x86/kernel/ima_arch.c | 17 +++++++++++++++++ > include/linux/ima.h | 9 +++++++++ > 3 files changed, 28 insertions(+) > create mode 100644 arch/x86/kernel/ima_arch.c > > diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile > index 02d6f5cf4e70..f32406e51424 100644 > --- a/arch/x86/kernel/Makefile > +++ b/arch/x86/kernel/Makefile > @@ -149,3 +149,5 @@ ifeq ($(CONFIG_X86_64),y) > obj-$(CONFIG_MMCONF_FAM10H) += mmconf-fam10h_64.o > obj-y += vsmp_64.o > endif > + > +obj-$(CONFIG_IMA) += ima_arch.o > diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c > new file mode 100644 > index 000000000000..bb5a88d2b271 > --- /dev/null > +++ b/arch/x86/kernel/ima_arch.c > @@ -0,0 +1,17 @@ > +/* SPDX-License-Identifier: GPL-2.0+ */ > +/* > + * Copyright (C) 2018 IBM Corporation > + */ > +#include <linux/efi.h> > +#include <linux/ima.h> > + > +extern struct boot_params boot_params; > + > +bool arch_ima_get_secureboot(void) > +{ > + if (efi_enabled(EFI_BOOT) && > + (boot_params.secure_boot == efi_secureboot_mode_enabled)) > + return true; > + else > + return false; > +} > diff --git a/include/linux/ima.h b/include/linux/ima.h > index 84806b54b50a..4852255aa4f4 100644 > --- a/include/linux/ima.h > +++ b/include/linux/ima.h > @@ -30,6 +30,15 @@ extern void ima_post_path_mknod(struct dentry *dentry); > extern void ima_add_kexec_buffer(struct kimage *image); > #endif > > +#ifdef CONFIG_X86 > +extern bool arch_ima_get_secureboot(void); > +#else > +static inline bool arch_ima_get_secureboot(void) > +{ > + return false; > +} > +#endif > + > #else > static inline int ima_bprm_check(struct linux_binprm *bprm) > { _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 2+ messages in thread
[parent not found: <20180926122210.14642-3-nayna@linux.vnet.ibm.com>]
* Re: [PATCH v4 2/6] ima: prevent kexec_load syscall based on runtime secureboot flag [not found] ` <20180926122210.14642-3-nayna@linux.vnet.ibm.com> @ 2018-09-27 11:33 ` Mimi Zohar 0 siblings, 0 replies; 2+ messages in thread From: Mimi Zohar @ 2018-09-27 11:33 UTC (permalink / raw) To: Nayna Jain, linux-integrity Cc: linux-efi, kexec, linux-kernel, dhowells, Seth Forshee, linux-security-module, jforbes [Cc'ing the kexec mailing list, and Seth] On Wed, 2018-09-26 at 17:52 +0530, Nayna Jain wrote: > When CONFIG_KEXEC_VERIFY_SIG is enabled, the kexec_file_load syscall > requires the kexec'd kernel image to be signed. Distros are concerned > about totally disabling the kexec_load syscall. As a compromise, the > kexec_load syscall will only be disabled when CONFIG_KEXEC_VERIFY_SIG > is configured and the system is booted with secureboot enabled. > > This patch disables the kexec_load syscall only for systems booted with > secureboot enabled. > > Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com> Nice! Mimi > --- > security/integrity/ima/ima_main.c | 17 +++++++++++------ > 1 file changed, 11 insertions(+), 6 deletions(-) > > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index dce0a8a217bb..bdb6e5563d05 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -505,20 +505,24 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, > */ > int ima_load_data(enum kernel_load_data_id id) > { > - bool sig_enforce; > + bool ima_enforce, sig_enforce; > > - if ((ima_appraise & IMA_APPRAISE_ENFORCE) != IMA_APPRAISE_ENFORCE) > - return 0; > + ima_enforce = > + (ima_appraise & IMA_APPRAISE_ENFORCE) == IMA_APPRAISE_ENFORCE; > > switch (id) { > case LOADING_KEXEC_IMAGE: > - if (ima_appraise & IMA_APPRAISE_KEXEC) { > +#ifdef CONFIG_KEXEC_VERIFY_SIG > + if (arch_ima_get_secureboot()) > + return -EACCES; > +#endif > + if (ima_enforce && (ima_appraise & IMA_APPRAISE_KEXEC)) { > pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n"); > return -EACCES; /* INTEGRITY_UNKNOWN */ > } > break; > case LOADING_FIRMWARE: > - if (ima_appraise & IMA_APPRAISE_FIRMWARE) { > + if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE)) { > pr_err("Prevent firmware sysfs fallback loading.\n"); > return -EACCES; /* INTEGRITY_UNKNOWN */ > } > @@ -526,7 +530,8 @@ int ima_load_data(enum kernel_load_data_id id) > case LOADING_MODULE: > sig_enforce = is_module_sig_enforced(); > > - if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES)) { > + if (ima_enforce && (!sig_enforce > + && (ima_appraise & IMA_APPRAISE_MODULES))) { > pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n"); > return -EACCES; /* INTEGRITY_UNKNOWN */ > } _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 2+ messages in thread
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2018-09-27 11:33 ` [PATCH v4 1/6] x86/ima: define arch_ima_get_secureboot Mimi Zohar
[not found] ` <20180926122210.14642-3-nayna@linux.vnet.ibm.com>
2018-09-27 11:33 ` [PATCH v4 2/6] ima: prevent kexec_load syscall based on runtime secureboot flag Mimi Zohar
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