Chester reports that it is necessary to introduce a new way to pass the EFI secure boot status between the EFI stub and the core kernel on ARM systems. The usual way of obtaining this information is by checking the SecureBoot and SetupMode EFI variables, but this can only be done after the EFI variable workqueue is created, which occurs in a subsys_initcall(), whereas arch_ima_get_secureboot() is called much earlier by the IMA framework. However, the IMA framework itself is started as a late_initcall, and the only reason the call to arch_ima_get_secureboot() occurs so early is because it happens in the context of a __setup() callback that parses the ima_appraise= command line parameter. So let's refactor this code a little bit, by using a core_param() callback to capture the command line argument, and deferring any reasoning based on its contents to the IMA init routine. Cc: Chester Lin <clin@xxxxxxxx> Cc: Mimi Zohar <zohar@xxxxxxxxxxxxx> Cc: Dmitry Kasatkin <dmitry.kasatkin@xxxxxxxxx> Cc: James Morris <jmorris@xxxxxxxxx> Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx> Link: https://lore.kernel.org/linux-arm-kernel/20200904072905.25332-2-clin@xxxxxxxx/ Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- v2: rebase onto series 'integrity: improve user feedback for invalid bootparams' include/linux/ima.h | 6 ++++++ security/integrity/ima/ima_appraise.c | 16 ++++++++++------ security/integrity/ima/ima_main.c | 1 + 3 files changed, 17 insertions(+), 6 deletions(-) diff --git a/include/linux/ima.h b/include/linux/ima.h index d15100de6cdd..8aefee9c36ab 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -27,6 +27,12 @@ extern void ima_post_path_mknod(struct dentry *dentry); extern int ima_file_hash(struct file *file, char *buf, size_t buf_size); extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size); +#ifdef CONFIG_IMA_APPRAISE_BOOTPARAM +extern void ima_appraise_parse_cmdline(void); +#else +static inline void ima_appraise_parse_cmdline(void) {} +#endif + #ifdef CONFIG_IMA_KEXEC extern void ima_add_kexec_buffer(struct kimage *image); #endif diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 3dd8c2e4314e..dfe08489faea 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -16,12 +16,19 @@ #include "ima.h" -static int __init default_appraise_setup(char *str) -{ #ifdef CONFIG_IMA_APPRAISE_BOOTPARAM +static char *ima_appraise_cmdline_default __initdata; +core_param(ima_appraise, ima_appraise_cmdline_default, charp, 0); + +void __init ima_appraise_parse_cmdline(void) +{ + const char *str = ima_appraise_cmdline_default; bool sb_state = arch_ima_get_secureboot(); int appraisal_state = ima_appraise; + if (!str) + return; + if (strncmp(str, "off", 3) == 0) appraisal_state = 0; else if (strncmp(str, "log", 3) == 0) @@ -42,11 +49,8 @@ static int __init default_appraise_setup(char *str) } else { ima_appraise = appraisal_state; } -#endif - return 1; } - -__setup("ima_appraise=", default_appraise_setup); +#endif /* * is_ima_appraise_enabled - return appraise status diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index a5a2ae36a36d..2497412b1ad2 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -865,6 +865,7 @@ static int __init init_ima(void) { int error; + ima_appraise_parse_cmdline(); ima_init_template_list(); hash_setup(CONFIG_IMA_DEFAULT_HASH); error = ima_init(); -- 2.17.1
