On Thu, May 31, 2018 at 11:23 AM, Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> wrote: > Both the init_module and finit_module syscalls call either directly > or indirectly the security_kernel_read_file LSM hook. This patch > replaces the direct call in init_module with a call to the new > security_kernel_load_data hook and makes the corresponding changes > in SELinux, LoadPin, and IMA. > > Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> > Cc: Jeff Vander Stoep <jeffv@xxxxxxxxxx> > Cc: Paul Moore <paul@xxxxxxxxxxxxxx> > Cc: Casey Schaufler <casey@xxxxxxxxxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > > --- > Changelog: > - For SELinux, have both the security_kernel_read_file and > security_kernel_load_data LSM hooks call selinux_kernel_read_file(). > - LoadPin: replace existing init_module LSM hook support with > new security_kernel_load_data hook. > > kernel/module.c | 2 +- > security/integrity/ima/ima_main.c | 24 ++++++++++-------------- > security/loadpin/loadpin.c | 15 +++++++++++++++ > security/selinux/hooks.c | 15 +++++++++++++++ > 4 files changed, 41 insertions(+), 15 deletions(-) As mentioned in the previous iteration, I have no strong opinion on the question of the LSM hooks, but the SELinux bits look okay to me. Acked-by: Paul Moore <paul@xxxxxxxxxxxxxx> > diff --git a/kernel/module.c b/kernel/module.c > index ce8066b88178..b97c642b5b4d 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -2879,7 +2879,7 @@ static int copy_module_from_user(const void __user *umod, unsigned long len, > if (info->len < sizeof(*(info->hdr))) > return -ENOEXEC; > > - err = security_kernel_read_file(NULL, READING_MODULE); > + err = security_kernel_load_data(LOADING_MODULE); > if (err) > return err; > > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index 5a7696152982..cd33a2eff496 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -438,17 +438,6 @@ static int read_idmap[READING_MAX_ID] = { > */ > int ima_read_file(struct file *file, enum kernel_read_file_id read_id) > { > - bool sig_enforce = is_module_sig_enforced(); > - > - if (!file && read_id == READING_MODULE) { > - if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES) && > - (ima_appraise & IMA_APPRAISE_ENFORCE)) { > - 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 */ > - } > - > if (read_id == READING_FIRMWARE_PREALLOC_BUFFER) { > if ((ima_appraise & IMA_APPRAISE_FIRMWARE) && > (ima_appraise & IMA_APPRAISE_ENFORCE)) { > @@ -487,9 +476,6 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, > return 0; > } > > - if (!file && read_id == READING_MODULE) /* MODULE_SIG_FORCE enabled */ > - return 0; > - > /* permit signed certs */ > if (!file && read_id == READING_X509_CERTIFICATE) > return 0; > @@ -518,6 +504,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, > */ > int ima_load_data(enum kernel_load_data_id id) > { > + bool sig_enforce; > + > if ((ima_appraise & IMA_APPRAISE_ENFORCE) != IMA_APPRAISE_ENFORCE) > return 0; > > @@ -533,6 +521,14 @@ int ima_load_data(enum kernel_load_data_id id) > pr_err("Prevent firmware sysfs fallback loading.\n"); > return -EACCES; /* INTEGRITY_UNKNOWN */ > } > + break; > + case LOADING_MODULE: > + sig_enforce = is_module_sig_enforced(); > + > + if (!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 */ > + } > default: > break; > } > diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c > index 5fa191252c8f..a9c07bfbc338 100644 > --- a/security/loadpin/loadpin.c > +++ b/security/loadpin/loadpin.c > @@ -173,9 +173,24 @@ static int loadpin_read_file(struct file *file, enum kernel_read_file_id id) > return 0; > } > > +static int loadpin_load_data(enum kernel_load_data_id id) > +{ > + int rc = 0; > + > + switch (id) { > + case LOADING_MODULE: > + rc = loadpin_read_file(NULL, READING_MODULE); > + default: > + break; > + } > + > + return rc; > +} > + > static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = { > LSM_HOOK_INIT(sb_free_security, loadpin_sb_free_security), > LSM_HOOK_INIT(kernel_read_file, loadpin_read_file), > + LSM_HOOK_INIT(kernel_load_data, loadpin_load_data), > }; > > void __init loadpin_add_hooks(void) > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 02ebd1585eaf..475aed9ee2c7 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -4059,6 +4059,20 @@ static int selinux_kernel_read_file(struct file *file, > return rc; > } > > +static int selinux_kernel_load_data(enum kernel_load_data_id id) > +{ > + int rc = 0; > + > + switch (id) { > + case LOADING_MODULE: > + rc = selinux_kernel_module_from_file(NULL); > + default: > + break; > + } > + > + return rc; > +} > + > static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) > { > return avc_has_perm(&selinux_state, > @@ -6950,6 +6964,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { > LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as), > LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as), > LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request), > + LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data), > LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file), > LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid), > LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid), > -- > 2.7.5 > -- paul moore www.paul-moore.com