diff options
| author |   Coiby Xu <coxu@redhat.com> | 2022-07-13 15:21:11 +0800 |
|---|---|---|
| committer |   Mimi Zohar <zohar@linux.ibm.com> | 2022-07-13 10:13:41 -0400 |
| commit | af16df54b89dee72df253abc5e7b5e8a6d16c11c (patch) | |
| tree | d236aeb2c9b99d9e452b6382f016d3e1bc92fc8f | |
| parent | ima: Fix a potential integer overflow in ima_appraise_measurement (diff) | |
| download | linux-dev-af16df54b89dee72df253abc5e7b5e8a6d16c11c.tar.xz linux-dev-af16df54b89dee72df253abc5e7b5e8a6d16c11c.zip | |
ima: force signature verification when CONFIG_KEXEC_SIG is configured
Currently, an unsigned kernel could be kexec'ed when IMA arch specific
policy is configured unless lockdown is enabled. Enforce kernel
signature verification check in the kexec_file_load syscall when IMA
arch specific policy is configured.
Fixes: 99d5cadfde2b ("kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE")
Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| -rw-r--r-- | include/linux/kexec.h | 6 | ||||
| -rw-r--r-- | kernel/kexec_file.c | 11 | ||||
| -rw-r--r-- | security/integrity/ima/ima_efi.c | 2 |
3 files changed, 18 insertions, 1 deletions
diff --git a/include/linux/kexec.h b/include/linux/kexec.h index ce6536f1d269..475683cd67f1 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -452,6 +452,12 @@ static inline int kexec_crash_loaded(void) { return 0; } #define kexec_in_progress false #endif /* CONFIG_KEXEC_CORE */ +#ifdef CONFIG_KEXEC_SIG +void set_kexec_sig_enforced(void); +#else +static inline void set_kexec_sig_enforced(void) {} +#endif + #endif /* !defined(__ASSEBMLY__) */ #endif /* LINUX_KEXEC_H */ diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 145321a5e798..f9261c07b048 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -29,6 +29,15 @@ #include <linux/vmalloc.h> #include "kexec_internal.h" +#ifdef CONFIG_KEXEC_SIG +static bool sig_enforce = IS_ENABLED(CONFIG_KEXEC_SIG_FORCE); + +void set_kexec_sig_enforced(void) +{ + sig_enforce = true; +} +#endif + static int kexec_calculate_store_digests(struct kimage *image); /* @@ -159,7 +168,7 @@ kimage_validate_signature(struct kimage *image) image->kernel_buf_len); if (ret) { - if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) { + if (sig_enforce) { pr_notice("Enforced kernel signature verification failed (%d).\n", ret); return ret; } diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c index 71786d01946f..9db66fe310d4 100644 --- a/security/integrity/ima/ima_efi.c +++ b/security/integrity/ima/ima_efi.c @@ -67,6 +67,8 @@ const char * const *arch_get_ima_policy(void) if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) { if (IS_ENABLED(CONFIG_MODULE_SIG)) set_module_sig_enforced(); + if (IS_ENABLED(CONFIG_KEXEC_SIG)) + set_kexec_sig_enforced(); return sb_arch_rules; } return NULL; |