[PATCH] ensure NULL deref can't possibly happen in is_exported()

[cascardo/linux.git] / kernel / module.c

diff --git a/kernel/module.c b/kernel/module.c
index 4fafd58..d75275d 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -127,7 +127,7 @@ extern const unsigned long __start___kcrctab_gpl_future[];
 #ifndef CONFIG_MODVERSIONS
 #define symversion(base, idx) NULL
 #else
-#define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL)
+#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
 #endif
 
 /* lookup symbol in given range of kernel_symbols */
@@ -705,14 +705,14 @@ EXPORT_SYMBOL(__symbol_put);
 
 void symbol_put_addr(void *addr)
 {
-       unsigned long flags;
+       struct module *modaddr;
 
-       spin_lock_irqsave(&modlist_lock, flags);
-       if (!kernel_text_address((unsigned long)addr))
-               BUG();
+       if (core_kernel_text((unsigned long)addr))
+               return;
 
-       module_put(module_text_address((unsigned long)addr));
-       spin_unlock_irqrestore(&modlist_lock, flags);
+       if (!(modaddr = module_text_address((unsigned long)addr)))
+               BUG();
+       module_put(modaddr);
 }
 EXPORT_SYMBOL_GPL(symbol_put_addr);
 
@@ -1254,6 +1254,7 @@ static inline int license_is_gpl_compatible(const char *license)
                || strcmp(license, "GPL v2") == 0
                || strcmp(license, "GPL and additional rights") == 0
                || strcmp(license, "Dual BSD/GPL") == 0
+               || strcmp(license, "Dual MIT/GPL") == 0
                || strcmp(license, "Dual MPL/GPL") == 0);
 }
 
@@ -1325,7 +1326,7 @@ int is_exported(const char *name, const struct module *mod)
        if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
                return 1;
        else
-               if (lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
+               if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
                        return 1;
                else
                        return 0;