diff options
author | Mimi Zohar <zohar@linux.vnet.ibm.com> | 2018-07-13 14:05:58 -0400 |
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committer | James Morris <james.morris@microsoft.com> | 2018-07-16 12:31:57 -0700 |
commit | 16c267aac86b463b1fcccd43c89f4c8e5c5c86fa (patch) | |
tree | 550e6fcb00d732a3c018b3258302f8ffd61a4379 /security/integrity/ima/ima_main.c | |
parent | a210fd32a46bae6d05b43860fe3b47732501d63b (diff) | |
download | linux-16c267aac86b463b1fcccd43c89f4c8e5c5c86fa.tar.bz2 |
ima: based on policy require signed kexec kernel images
The original kexec_load syscall can not verify file signatures, nor can
the kexec image be measured. Based on policy, deny the kexec_load
syscall.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
Diffstat (limited to 'security/integrity/ima/ima_main.c')
-rw-r--r-- | security/integrity/ima/ima_main.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index dca44cf7838e..71fecfef0939 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -496,6 +496,33 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, MAY_READ, func, 0); } +/** + * ima_load_data - appraise decision based on policy + * @id: kernel load data caller identifier + * + * Callers of this LSM hook can not measure, appraise, or audit the + * data provided by userspace. Enforce policy rules requring a file + * signature (eg. kexec'ed kernel image). + * + * For permission return 0, otherwise return -EACCES. + */ +int ima_load_data(enum kernel_load_data_id id) +{ + if ((ima_appraise & IMA_APPRAISE_ENFORCE) != IMA_APPRAISE_ENFORCE) + return 0; + + switch (id) { + case LOADING_KEXEC_IMAGE: + if (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 */ + } + default: + break; + } + return 0; +} + static int __init init_ima(void) { int error; |