livepatch module author can pass module name/old function name with more than the defined character limit. With obj->name length greater than MODULE_NAME_LEN, the livepatch module gets loaded but waits forever on the module specified by obj->name to be loaded. It also populates a /sys directory with an untruncated object name. In the case of funcs->old_name length greater then KSYM_NAME_LEN, it would not match against any of the symbol table entries. Instead loop through the symbol table comparing them against a nonexisting function, which can be avoided. The same issues apply, to misspelled/incorrect names. At least gatekeep the modules with over the limit string length, by checking for their length during livepatch module registration. Signed-off-by: Kamalesh Babulal <kamalesh@xxxxxxxxxxxxxxxxxx> --- kernel/livepatch/core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 3a4656fb7047..5b77a7314e01 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -678,6 +678,9 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func) if (!func->old_name || !func->new_func) return -EINVAL; + if (strlen(func->old_name) >= KSYM_NAME_LEN) + return -EINVAL; + INIT_LIST_HEAD(&func->stack_node); func->patched = false; func->transition = false; @@ -751,6 +754,9 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj) if (!obj->funcs) return -EINVAL; + if (klp_is_module(obj) && strlen(obj->name) >= MODULE_NAME_LEN) + return -EINVAL; + obj->patched = false; obj->mod = NULL; -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
