diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index de1e29fa467e..fb690539d5f6 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1264,7 +1264,11 @@ static int resize_reference_state(struct bpf_func_state *state, size_t n) */ static int grow_stack_state(struct bpf_verifier_env *env, struct bpf_func_state *state, int size) { - size_t old_n = state->allocated_stack / BPF_REG_SIZE, n = size / BPF_REG_SIZE; + size_t old_n = state->allocated_stack / BPF_REG_SIZE, n; + + /* The stack size is always a multiple of BPF_REG_SIZE. */ + size = round_up(size, BPF_REG_SIZE); + n = size / BPF_REG_SIZE; if (old_n >= n) return 0; @@ -6638,7 +6642,10 @@ static int check_stack_access_within_bounds( return err; } - return grow_stack_state(env, state, round_up(-min_off, BPF_REG_SIZE)); + /* Note that there is no stack access with offset zero, so the needed stack + * size is -min_off, not -min_off+1. + */ + return grow_stack_state(env, state, -min_off /* size */); } /* check whether memory at (regno + off) is accessible for t = (read | write) |