On Thu, Nov 02, 2017 at 12:05:52PM +0100, Arnd Bergmann wrote: > The bpf_verifer_ops array is generated dynamically and may be > empty depending on configuration, which then causes an out > of bounds access: > > kernel/bpf/verifier.c: In function 'bpf_check': > kernel/bpf/verifier.c:4320:29: error: array subscript is above array bounds > [-Werror=array-bounds] > > This adds a check to the start of the function as a workaround. > I would assume that the function is never called in that configuration, > so the warning is probably harmless. > > Fixes: 00176a34d9e2 ("bpf: remove the verifier ops from program structure") > Signed-off-by: Arnd Bergmann <a...@arndb.de> > --- > Since there hasn't been a linux-next release in two weeks, I'm not > entirely sure this is still needed, but from looking of the net-next > contents it seems it is. I did not check any other trees that might > have a fix already. > --- > kernel/bpf/verifier.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index 750aff880ecb..debb60ad08ee 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -4447,6 +4447,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr > *attr) > struct bpf_verifer_log *log; > int ret = -EINVAL; > > + /* no program is valid */ > + if (ARRAY_SIZE(bpf_verifier_ops) == 0) > + return -EINVAL;
sorry I don't see how bpf_verifier_ops can be empty. Did you mix it up with your previous patch when you made bpf_analyzer_ops empty?