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-rw-r--r--kernel/module.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 5d9078d6f0fa..fb6f091f5940 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1204,6 +1204,39 @@ void *__symbol_get(const char *symbol)
}
EXPORT_SYMBOL_GPL(__symbol_get);
+/*
+ * Ensure that an exported symbol [global namespace] does not already exist
+ * in the Kernel or in some other modules exported symbol table.
+ */
+static int verify_export_symbols(struct module *mod)
+{
+ const char *name = NULL;
+ unsigned long i, ret = 0;
+ struct module *owner;
+ const unsigned long *crc;
+
+ for (i = 0; i < mod->num_syms; i++)
+ if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
+ name = mod->syms[i].name;
+ ret = -ENOEXEC;
+ goto dup;
+ }
+
+ for (i = 0; i < mod->num_gpl_syms; i++)
+ if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
+ name = mod->gpl_syms[i].name;
+ ret = -ENOEXEC;
+ goto dup;
+ }
+
+dup:
+ if (ret)
+ printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
+ mod->name, name, module_name(owner));
+
+ return ret;
+}
+
/* Change all symbols so that sh_value encodes the pointer directly. */
static int simplify_symbols(Elf_Shdr *sechdrs,
unsigned int symindex,
@@ -1772,6 +1805,12 @@ static struct module *load_module(void __user *umod,
goto cleanup;
}
+ /* Find duplicate symbols */
+ err = verify_export_symbols(mod);
+
+ if (err < 0)
+ goto cleanup;
+
/* Set up and sort exception table */
mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
mod->extable = extable = (void *)sechdrs[exindex].sh_addr;