On Sun, Nov 11, 2018 at 11:10:17PM +0800, Zhizhou Zhang wrote: > ftrace_ops_test() passed local varible parameter to hash_contains_ip(), > which could result KASAN stack-out-of-bounds warning. > > Signed-off-by: Zhizhou Zhang <zhizhouzh...@asrmicro.com> > --- > kernel/trace/ftrace.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index f536f60..6e11f90 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -1522,6 +1522,8 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long > ip, void *regs) > rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); > rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); > > + kasan_unpoison_task_stack(current);
This is extremely heavy-handed, and will mask legitimate stack-out-of-bounds errors. Passing a stack-local variable by reference *should not* result in KASAN warnings unless KASAN itself is broken. Can you please give an example report when this occurs? Which compiler are you using? Thanks, Mark. > + > if (hash_contains_ip(ip, &hash)) > ret = 1; > else > -- > 2.7.4 >
