The original kexec_load syscall can not verify file signatures. This patch differentiates between the kexec_load and kexec_file_load syscalls.
Signed-off-by: Mimi Zohar <[email protected]> Cc: Eric Biederman <[email protected]> Cc: Luis R. Rodriguez <[email protected]> Cc: Kees Cook <[email protected]> Cc: David Howells <[email protected]> Changelog v3: - use switch/case --- security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_main.c | 22 +++++++++++++++++----- security/integrity/ima/ima_policy.c | 2 ++ 3 files changed, 20 insertions(+), 5 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 354bb5716ce3..78c15264b17b 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -232,6 +232,7 @@ int ima_policy_show(struct seq_file *m, void *v); #define IMA_APPRAISE_MODULES 0x08 #define IMA_APPRAISE_FIRMWARE 0x10 #define IMA_APPRAISE_POLICY 0x20 +#define IMA_APPRAISE_KEXEC 0x40 #ifdef CONFIG_IMA_APPRAISE int ima_appraise_measurement(enum ima_hooks func, diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index eeb7075868db..fbbcc02a1380 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -432,15 +432,27 @@ void ima_post_path_mknod(struct dentry *dentry) */ int ima_read_data(struct file *file, enum kernel_read_file_id read_id) { - bool sig_enforce = is_module_sig_enforced(); + bool sig_enforce; - if (!file && read_id == READING_MODULE) { - if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES) && - (ima_appraise & IMA_APPRAISE_ENFORCE)) { + if ((ima_appraise & IMA_APPRAISE_ENFORCE) != IMA_APPRAISE_ENFORCE) + return 0; + + switch (read_id) { + case READING_MODULE: + sig_enforce = is_module_sig_enforced(); /* appended sig */ + if (!file && !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 */ } - return 0; /* We rely on module signature checking */ + break; + case READING_KEXEC_IMAGE: + if (!file && (ima_appraise & IMA_APPRAISE_KEXEC)) { + pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file syscall.\n"); + return -EACCES; /* INTEGRITY_UNKNOWN */ + } + default: + break; } return 0; } diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 8bbc18eb07eb..c27f6993b07a 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -448,6 +448,8 @@ static int ima_appraise_flag(enum ima_hooks func) return IMA_APPRAISE_FIRMWARE; else if (func == POLICY_CHECK) return IMA_APPRAISE_POLICY; + else if (func == KEXEC_KERNEL_CHECK) + return IMA_APPRAISE_KEXEC; return 0; } -- 2.7.5
