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-rw-r--r--init/Kconfig9
-rw-r--r--kernel/module.c44
2 files changed, 38 insertions, 15 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 6a44defac3e..f0e62e5ce0d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -825,6 +825,15 @@ menuconfig MODULES
If unsure, say Y.
+config MODULE_FORCE_LOAD
+ bool "Forced module loading"
+ depends on MODULES
+ default n
+ help
+ This option allows loading of modules even if that would set the
+ 'F' (forced) taint, due to lack of version info. Which is
+ usually a really bad idea.
+
config MODULE_UNLOAD
bool "Module unloading"
depends on MODULES
diff --git a/kernel/module.c b/kernel/module.c
index 8674a390a2e..8e4528c9909 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -890,6 +890,19 @@ static struct module_attribute *modinfo_attrs[] = {
static const char vermagic[] = VERMAGIC_STRING;
+static int try_to_force_load(struct module *mod, const char *symname)
+{
+#ifdef CONFIG_MODULE_FORCE_LOAD
+ if (!(tainted & TAINT_FORCED_MODULE))
+ printk("%s: no version for \"%s\" found: kernel tainted.\n",
+ mod->name, symname);
+ add_taint_module(mod, TAINT_FORCED_MODULE);
+ return 0;
+#else
+ return -ENOEXEC;
+#endif
+}
+
#ifdef CONFIG_MODVERSIONS
static int check_version(Elf_Shdr *sechdrs,
unsigned int versindex,
@@ -914,18 +927,18 @@ static int check_version(Elf_Shdr *sechdrs,
if (versions[i].crc == *crc)
return 1;
- printk("%s: disagrees about version of symbol %s\n",
- mod->name, symname);
DEBUGP("Found checksum %lX vs module %lX\n",
*crc, versions[i].crc);
- return 0;
+ goto bad_version;
}
- /* Not in module's version table. OK, but that taints the kernel. */
- if (!(tainted & TAINT_FORCED_MODULE))
- printk("%s: no version for \"%s\" found: kernel tainted.\n",
- mod->name, symname);
- add_taint_module(mod, TAINT_FORCED_MODULE);
- return 1;
+
+ if (!try_to_force_load(mod, symname))
+ return 1;
+
+bad_version:
+ printk("%s: disagrees about version of symbol %s\n",
+ mod->name, symname);
+ return 0;
}
static inline int check_modstruct_version(Elf_Shdr *sechdrs,
@@ -1853,9 +1866,9 @@ static struct module *load_module(void __user *umod,
modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
/* This is allowed: modprobe --force will invalidate it. */
if (!modmagic) {
- add_taint_module(mod, TAINT_FORCED_MODULE);
- printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
- mod->name);
+ err = try_to_force_load(mod, "magic");
+ if (err)
+ goto free_hdr;
} else if (!same_magic(modmagic, vermagic)) {
printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
mod->name, modmagic, vermagic);
@@ -2006,9 +2019,10 @@ static struct module *load_module(void __user *umod,
(mod->num_gpl_future_syms && !gplfuturecrcindex) ||
(mod->num_unused_syms && !unusedcrcindex) ||
(mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
- printk(KERN_WARNING "%s: No versions for exported symbols."
- " Tainting kernel.\n", mod->name);
- add_taint_module(mod, TAINT_FORCED_MODULE);
+ printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name);
+ err = try_to_force_load(mod, "nocrc");
+ if (err)
+ goto cleanup;
}
#endif
markersindex = find_sec(hdr, sechdrs, secstrings, "__markers");