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bpf: Use correct permission flag for mixed signed bounds arithmetic

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We forbid adding unknown scalars with mixed signed bounds due to the
spectre v1 masking mitigation. Hence this also needs bypass_spec_v1
flag instead of allow_ptr_leaks.

Fixes: 2c78ee898d ("bpf: Implement CAP_BPF")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Daniel Borkmann 2021-03-23 08:32:59 +01:00
parent afd0be7299
commit 9601148392
1 changed files with 1 additions and 1 deletions
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kernel/bpf/verifier.c
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@ -6085,7 +6085,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
dst, reg_type_str[ptr_reg->type]);
return -EACCES;
case PTR_TO_MAP_VALUE:
if (!env->allow_ptr_leaks && !known && (smin_val < 0) != (smax_val < 0)) {
if (!env->env->bypass_spec_v1 && !known && (smin_val < 0) != (smax_val < 0)) {
verbose(env, "R%d has unknown scalar with mixed signed bounds, pointer arithmetic with it prohibited for !root\n",
off_reg == dst_reg ? dst : src);
return -EACCES;