Messages in this thread Patch in this message | | | Date | Mon, 4 Jun 2018 11:19:37 +0200 | From | Jessica Yu <> | Subject | Re: [PATCH v4a 8/8] module: replace the existing LSM hook in init_module |
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+++ Mimi Zohar [31/05/18 11:23 -0400]: >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@linux.vnet.ibm.com> >Cc: Jeff Vander Stoep <jeffv@google.com> >Cc: Paul Moore <paul@paul-moore.com> >Cc: Casey Schaufler <casey@schaufler-ca.com> >Cc: Kees Cook <keescook@chromium.org>
For the module.c parts:
Acked-by: Jessica Yu <jeyu@kernel.org>
>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(-) > >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 >
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