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-rw-r--r--kernel/module.c93
1 files changed, 92 insertions, 1 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 74bc195..68c564e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -58,6 +58,7 @@
#include <linux/jump_label.h>
#include <linux/pfn.h>
#include <linux/bsearch.h>
+#include "module-internal.h"
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
@@ -102,6 +103,43 @@ static LIST_HEAD(modules);
struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
#endif /* CONFIG_KGDB_KDB */
+#ifdef CONFIG_MODULE_SIG
+#ifdef CONFIG_MODULE_SIG_FORCE
+static bool sig_enforce = true;
+#else
+static bool sig_enforce = false;
+
+static int param_set_bool_enable_only(const char *val,
+ const struct kernel_param *kp)
+{
+ int err;
+ bool test;
+ struct kernel_param dummy_kp = *kp;
+
+ dummy_kp.arg = &test;
+
+ err = param_set_bool(val, &dummy_kp);
+ if (err)
+ return err;
+
+ /* Don't let them unset it once it's set! */
+ if (!test && sig_enforce)
+ return -EROFS;
+
+ if (test)
+ sig_enforce = true;
+ return 0;
+}
+
+static const struct kernel_param_ops param_ops_bool_enable_only = {
+ .set = param_set_bool_enable_only,
+ .get = param_get_bool,
+};
+#define param_check_bool_enable_only param_check_bool
+
+module_param(sig_enforce, bool_enable_only, 0644);
+#endif /* !CONFIG_MODULE_SIG_FORCE */
+#endif /* CONFIG_MODULE_SIG */
/* Block module loading/unloading? */
int modules_disabled = 0;
@@ -136,6 +174,7 @@ struct load_info {
unsigned long symoffs, stroffs;
struct _ddebug *debug;
unsigned int num_debug;
+ bool sig_ok;
struct {
unsigned int sym, str, mod, vers, info, pcpu;
} index;
@@ -2379,7 +2418,49 @@ static inline void kmemleak_load_module(const struct module *mod,
}
#endif
-/* Sets info->hdr and info->len. */
+#ifdef CONFIG_MODULE_SIG
+static int module_sig_check(struct load_info *info,
+ const void *mod, unsigned long *len)
+{
+ int err = -ENOKEY;
+ const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
+ const void *p = mod, *end = mod + *len;
+
+ /* Poor man's memmem. */
+ while ((p = memchr(p, MODULE_SIG_STRING[0], end - p))) {
+ if (p + markerlen > end)
+ break;
+
+ if (memcmp(p, MODULE_SIG_STRING, markerlen) == 0) {
+ const void *sig = p + markerlen;
+ /* Truncate module up to signature. */
+ *len = p - mod;
+ err = mod_verify_sig(mod, *len, sig, end - sig);
+ break;
+ }
+ p++;
+ }
+
+ if (!err) {
+ info->sig_ok = true;
+ return 0;
+ }
+
+ /* Not having a signature is only an error if we're strict. */
+ if (err == -ENOKEY && !sig_enforce)
+ err = 0;
+
+ return err;
+}
+#else /* !CONFIG_MODULE_SIG */
+static int module_sig_check(struct load_info *info,
+ void *mod, unsigned long *len)
+{
+ return 0;
+}
+#endif /* !CONFIG_MODULE_SIG */
+
+/* Sets info->hdr, info->len and info->sig_ok. */
static int copy_and_check(struct load_info *info,
const void __user *umod, unsigned long len,
const char __user *uargs)
@@ -2399,6 +2480,10 @@ static int copy_and_check(struct load_info *info,
goto free_hdr;
}
+ err = module_sig_check(info, hdr, &len);
+ if (err)
+ goto free_hdr;
+
/* Sanity checks against insmoding binaries or wrong arch,
weird elf version */
if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
@@ -2884,6 +2969,12 @@ static struct module *load_module(void __user *umod,
goto free_copy;
}
+#ifdef CONFIG_MODULE_SIG
+ mod->sig_ok = info.sig_ok;
+ if (!mod->sig_ok)
+ add_taint_module(mod, TAINT_FORCED_MODULE);
+#endif
+
/* Now module is in final location, initialize linked lists, etc. */
err = module_unload_init(mod);
if (err)
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