From 0914ade209c452cff6a29b1c0ae6fff3167fa1d0 Mon Sep 17 00:00:00 2001 From: Nayna Jain Date: Tue, 9 Oct 2018 23:00:33 +0530 Subject: x86/ima: define arch_ima_get_secureboot 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 Suggested-by: Seth Forshee Cc: David Howells Cc: Eric Biederman Cc: Peter Jones Cc: Vivek Goyal Cc: Dave Young Signed-off-by: Mimi Zohar --- include/linux/ima.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/ima.h') diff --git a/include/linux/ima.h b/include/linux/ima.h index 97914a2833d1..948135fb60f1 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) { -- cgit v1.2.3 From 6191706246de99ff2fac4b6f157f20205a0943cd Mon Sep 17 00:00:00 2001 From: Nayna Jain Date: Tue, 9 Oct 2018 23:00:36 +0530 Subject: ima: add support for arch specific policies Builtin IMA policies can be enabled on the boot command line, and replaced with a custom policy, normally during early boot in the initramfs. Build time IMA policy rules were recently added. These rules are automatically enabled on boot and persist after loading a custom policy. There is a need for yet another type of policy, an architecture specific policy, which is derived at runtime during kernel boot, based on the runtime secure boot flags. Like the build time policy rules, these rules persist after loading a custom policy. This patch adds support for loading an architecture specific IMA policy. Signed-off-by: Nayna Jain Co-Developed-by: Mimi Zohar Signed-off-by: Mimi Zohar --- include/linux/ima.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/ima.h') diff --git a/include/linux/ima.h b/include/linux/ima.h index 948135fb60f1..62c5241b0899 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -39,6 +39,11 @@ static inline bool arch_ima_get_secureboot(void) } #endif +static inline const char * const *arch_get_ima_policy(void) +{ + return NULL; +} + #else static inline int ima_bprm_check(struct linux_binprm *bprm) { -- cgit v1.2.3 From d958083a8f6408e76850bc7394976050d7e43173 Mon Sep 17 00:00:00 2001 From: Eric Richter Date: Tue, 9 Oct 2018 23:00:37 +0530 Subject: x86/ima: define arch_get_ima_policy() for x86 On x86, there are two methods of verifying a kexec'ed kernel image signature being loaded via the kexec_file_load syscall - an architecture specific implementaton or a IMA KEXEC_KERNEL_CHECK appraisal rule. Neither of these methods verify the kexec'ed kernel image signature being loaded via the kexec_load syscall. Secure boot enabled systems require kexec images to be signed. Therefore, this patch loads an IMA KEXEC_KERNEL_CHECK policy rule on secure boot enabled systems not configured with CONFIG_KEXEC_VERIFY_SIG enabled. When IMA_APPRAISE_BOOTPARAM is configured, different IMA appraise modes (eg. fix, log) can be specified on the boot command line, allowing unsigned or invalidly signed kernel images to be kexec'ed. This patch permits enabling IMA_APPRAISE_BOOTPARAM or IMA_ARCH_POLICY, but not both. Signed-off-by: Eric Richter Signed-off-by: Nayna Jain Cc: David Howells Cc: Eric Biederman Cc: Peter Jones Cc: Vivek Goyal Cc: Dave Young Signed-off-by: Mimi Zohar --- include/linux/ima.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/ima.h') diff --git a/include/linux/ima.h b/include/linux/ima.h index 62c5241b0899..5ab9134d4fd7 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -32,17 +32,18 @@ extern void ima_add_kexec_buffer(struct kimage *image); #ifdef CONFIG_X86 extern bool arch_ima_get_secureboot(void); +extern const char * const *arch_get_ima_policy(void); #else static inline bool arch_ima_get_secureboot(void) { return false; } -#endif static inline const char * const *arch_get_ima_policy(void) { return NULL; } +#endif #else static inline int ima_bprm_check(struct linux_binprm *bprm) -- cgit v1.2.3 From 399574c64eaf94e82b7cf056978d7e68748c0f1d Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Sun, 18 Nov 2018 04:08:12 -0500 Subject: x86/ima: retry detecting secure boot mode The secure boot mode may not be detected on boot for some reason (eg. buggy firmware). This patch attempts one more time to detect the secure boot mode. Signed-off-by: Mimi Zohar --- include/linux/ima.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/ima.h') diff --git a/include/linux/ima.h b/include/linux/ima.h index 5ab9134d4fd7..b5e16b8c50b7 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -30,7 +30,7 @@ extern void ima_post_path_mknod(struct dentry *dentry); extern void ima_add_kexec_buffer(struct kimage *image); #endif -#ifdef CONFIG_X86 +#if defined(CONFIG_X86) && defined(CONFIG_EFI) extern bool arch_ima_get_secureboot(void); extern const char * const *arch_get_ima_policy(void); #else -- cgit v1.2.3 From fdb2410f7702f25f82804a261f90ad03422bd2c3 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 22 Jan 2019 14:06:49 -0600 Subject: ima: define ima_post_create_tmpfile() hook and add missing call If tmpfiles can be made persistent, then newly created tmpfiles need to be treated like any other new files in policy. This patch indicates which newly created tmpfiles are in policy, causing the file hash to be calculated on __fput(). Reported-by: Ignaz Forster [rgoldwyn@suse.com: Call ima_post_create_tmpfile() in vfs_tmpfile() as opposed to do_tmpfile(). This will help the case for overlayfs where copy_up is denied while overwriting a file.] Signed-off-by: Goldwyn Rodrigues Signed-off-by: Mimi Zohar --- include/linux/ima.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/ima.h') diff --git a/include/linux/ima.h b/include/linux/ima.h index b5e16b8c50b7..dc12fbcf484c 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -18,6 +18,7 @@ struct linux_binprm; #ifdef CONFIG_IMA extern int ima_bprm_check(struct linux_binprm *bprm); extern int ima_file_check(struct file *file, int mask); +extern void ima_post_create_tmpfile(struct inode *inode); extern void ima_file_free(struct file *file); extern int ima_file_mmap(struct file *file, unsigned long prot); extern int ima_load_data(enum kernel_load_data_id id); @@ -56,6 +57,10 @@ static inline int ima_file_check(struct file *file, int mask) return 0; } +static inline void ima_post_create_tmpfile(struct inode *inode) +{ +} + static inline void ima_file_free(struct file *file) { return; -- cgit v1.2.3