bpf: Move sanitize_val_alu out of op switch

commit f528819334881fd622fdadeddb3f7edaed8b7c9b upstream.

Add a small sanitize_needed() helper function and move sanitize_val_alu()
out of the main opcode switch. In upcoming work, we'll move sanitize_ptr_alu()
as well out of its opcode switch so this helps to streamline both.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Daniel Borkmann 2021-03-24 11:25:39 +01:00 committed by Greg Kroah-Hartman
parent 7723d32438
commit fbe6603e7c

View File

@ -5417,6 +5417,11 @@ static int sanitize_val_alu(struct bpf_verifier_env *env,
return update_alu_sanitation_state(aux, BPF_ALU_NON_POINTER, 0); return update_alu_sanitation_state(aux, BPF_ALU_NON_POINTER, 0);
} }
static bool sanitize_needed(u8 opcode)
{
return opcode == BPF_ADD || opcode == BPF_SUB;
}
static int sanitize_ptr_alu(struct bpf_verifier_env *env, static int sanitize_ptr_alu(struct bpf_verifier_env *env,
struct bpf_insn *insn, struct bpf_insn *insn,
const struct bpf_reg_state *ptr_reg, const struct bpf_reg_state *ptr_reg,
@ -6389,6 +6394,12 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
return 0; return 0;
} }
if (sanitize_needed(opcode)) {
ret = sanitize_val_alu(env, insn);
if (ret < 0)
return sanitize_err(env, insn, ret, NULL, NULL);
}
/* Calculate sign/unsigned bounds and tnum for alu32 and alu64 bit ops. /* Calculate sign/unsigned bounds and tnum for alu32 and alu64 bit ops.
* There are two classes of instructions: The first class we track both * There are two classes of instructions: The first class we track both
* alu32 and alu64 sign/unsigned bounds independently this provides the * alu32 and alu64 sign/unsigned bounds independently this provides the
@ -6405,17 +6416,11 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
*/ */
switch (opcode) { switch (opcode) {
case BPF_ADD: case BPF_ADD:
ret = sanitize_val_alu(env, insn);
if (ret < 0)
return sanitize_err(env, insn, ret, NULL, NULL);
scalar32_min_max_add(dst_reg, &src_reg); scalar32_min_max_add(dst_reg, &src_reg);
scalar_min_max_add(dst_reg, &src_reg); scalar_min_max_add(dst_reg, &src_reg);
dst_reg->var_off = tnum_add(dst_reg->var_off, src_reg.var_off); dst_reg->var_off = tnum_add(dst_reg->var_off, src_reg.var_off);
break; break;
case BPF_SUB: case BPF_SUB:
ret = sanitize_val_alu(env, insn);
if (ret < 0)
return sanitize_err(env, insn, ret, NULL, NULL);
scalar32_min_max_sub(dst_reg, &src_reg); scalar32_min_max_sub(dst_reg, &src_reg);
scalar_min_max_sub(dst_reg, &src_reg); scalar_min_max_sub(dst_reg, &src_reg);
dst_reg->var_off = tnum_sub(dst_reg->var_off, src_reg.var_off); dst_reg->var_off = tnum_sub(dst_reg->var_off, src_reg.var_off);