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-rw-r--r--kernel/bpf/verifier.c16
-rw-r--r--tools/testing/selftests/bpf/test_verifier.c13
2 files changed, 25 insertions, 4 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 9d25506bd55a..2e70b813a1a7 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3583,12 +3583,15 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
return err;
if (BPF_SRC(insn->code) == BPF_X) {
+ struct bpf_reg_state *src_reg = regs + insn->src_reg;
+ struct bpf_reg_state *dst_reg = regs + insn->dst_reg;
+
if (BPF_CLASS(insn->code) == BPF_ALU64) {
/* case: R1 = R2
* copy register state to dest reg
*/
- regs[insn->dst_reg] = regs[insn->src_reg];
- regs[insn->dst_reg].live |= REG_LIVE_WRITTEN;
+ *dst_reg = *src_reg;
+ dst_reg->live |= REG_LIVE_WRITTEN;
} else {
/* R1 = (u32) R2 */
if (is_pointer_value(env, insn->src_reg)) {
@@ -3596,9 +3599,14 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
"R%d partial copy of pointer\n",
insn->src_reg);
return -EACCES;
+ } else if (src_reg->type == SCALAR_VALUE) {
+ *dst_reg = *src_reg;
+ dst_reg->live |= REG_LIVE_WRITTEN;
+ } else {
+ mark_reg_unknown(env, regs,
+ insn->dst_reg);
}
- mark_reg_unknown(env, regs, insn->dst_reg);
- coerce_reg_to_size(&regs[insn->dst_reg], 4);
+ coerce_reg_to_size(dst_reg, 4);
}
} else {
/* case: R = imm
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 36ce58b4933e..957e4711c46c 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -2960,6 +2960,19 @@ static struct bpf_test tests[] = {
.result = ACCEPT,
},
{
+ "alu32: mov u32 const",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_7, 0),
+ BPF_ALU32_IMM(BPF_AND, BPF_REG_7, 1),
+ BPF_MOV32_REG(BPF_REG_0, BPF_REG_7),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_7, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .retval = 0,
+ },
+ {
"unpriv: partial copy of pointer",
.insns = {
BPF_MOV32_REG(BPF_REG_1, BPF_REG_10),