From ee20433f60ae34b52fb11e8f70a8f6139252eb68 Mon Sep 17 00:00:00 2001 From: Kamalesh Babulal Date: Fri, 20 Jul 2018 15:16:42 +0530 Subject: livepatch: Validate module/old func name length commit 6e9df95b76cad18f7b217bdad7bb8a26d63b8c47 upstream. 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. Cc: stable@vger.kernel.org Signed-off-by: Kamalesh Babulal Acked-by: Josh Poimboeuf Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- kernel/livepatch/core.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel') 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; -- cgit v1.2.3