On Tue, Nov 29, 2016 at 12:27:09PM -0500, Josef Bacik wrote:
> If we have a branch that looks something like this
>
> int foo = map->value;
> if (condition) {
> foo += blah;
> } else {
> foo = bar;
> }
> map->array[foo] = baz;
>
> We will incorrectly assume that the !condition branch is equal to the
> condition
> branch as the register for foo will be UNKNOWN_VALUE in both cases. We need
> to
> adjust this logic to only do this if we didn't do a varlen access after we
> processed the !condition branch, otherwise we have different ranges and need
> to
> check the other branch as well.
>
> Fixes: 484611357c19 ("bpf: allow access into map value arrays")
> Reported-by: Jann Horn <[email protected]>
> Signed-off-by: Josef Bacik <[email protected]>
Thank you!
Acked-by: Alexei Starovoitov <[email protected]>
