On Fri, Jul 20, 2018 at 03:16:42PM +0530, Kamalesh Babulal wrote: > 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 <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]> > --- > 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 > -- Josh
