MUL instruction required that src_reg would be a known value (i.e. src_reg would be a const value). The condition in this case can be relaxed, since the range computation algorithm used in current code already supports a proper range computation for any valid range value on its operands. Signed-off-by: Cupertino Miranda <cupertino.miranda@xxxxxxxxxx> Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx> Acked-by: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> Cc: Yonghong Song <yonghong.song@xxxxxxxxx> Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> Cc: David Faust <david.faust@xxxxxxxxxx> Cc: Jose Marchesi <jose.marchesi@xxxxxxxxxx> Cc: Elena Zannoni <elena.zannoni@xxxxxxxxxx> Cc: Eduard Zingerman <eddyz87@xxxxxxxxx> Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> --- kernel/bpf/verifier.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 54aca9b377a4..b6344cead2e2 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13746,12 +13746,8 @@ static bool is_safe_to_compute_dst_reg_range(struct bpf_insn *insn, case BPF_AND: case BPF_XOR: case BPF_OR: - return true; - - /* Compute range for the following only if the src_reg is const. - */ case BPF_MUL: - return src_is_const; + return true; /* Shift operators range is only computable if shift dimension operand * is a constant. Shifts greater than 31 or 63 are undefined. This -- 2.39.2
