@@ -6436,6 +6436,11 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
src_reg = NULL;
if (dst_reg->type != SCALAR_VALUE)
ptr_reg = dst_reg;
+ else
+ /* Make sure ID is cleared otherwise dst_reg min/max could be
+ * incorrectly propagated into other registers by find_equal_scalars()
+ */
+ dst_reg->id = 0;
if (BPF_SRC(insn->code) == BPF_X) {
src_reg = ®s[insn->src_reg];
if (src_reg->type != SCALAR_VALUE) {
@@ -6569,6 +6574,12 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
/* case: R1 = R2
* copy register state to dest reg
*/
+ if (src_reg->type == SCALAR_VALUE && !src_reg->id)
+ /* Assign src and dst registers the same ID
+ * that will be used by find_equal_scalars()
+ * to propagate min/max range.
+ */
+ src_reg->id = ++env->id_gen;
*dst_reg = *src_reg;
dst_reg->live |= REG_LIVE_WRITTEN;
dst_reg->subreg_def = DEF_NOT_SUBREG;
@@ -6581,6 +6592,11 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
return -EACCES;
} else if (src_reg->type == SCALAR_VALUE) {
*dst_reg = *src_reg;
+ /* Make sure ID is cleared otherwise
+ * dst_reg min/max could be incorrectly
+ * propagated into src_reg by find_equal_scalars()
+ */
+ dst_reg->id = 0;
dst_reg->live |= REG_LIVE_WRITTEN;
dst_reg->subreg_def = env->insn_idx + 1;
} else {
@@ -7369,6 +7385,30 @@ static bool try_match_pkt_pointers(const struct bpf_insn *insn,
return true;
}
+static void find_equal_scalars(struct bpf_verifier_state *vstate,
+ struct bpf_reg_state *known_reg)
+{
+ struct bpf_func_state *state;
+ struct bpf_reg_state *reg;
+ int i, j;
+
+ for (i = 0; i <= vstate->curframe; i++) {
+ state = vstate->frame[i];
+ for (j = 0; j < MAX_BPF_REG; j++) {
+ reg = &state->regs[j];
+ if (reg->type == SCALAR_VALUE && reg->id == known_reg->id)
+ *reg = *known_reg;
+ }
+
+ bpf_for_each_spilled_reg(j, state, reg) {
+ if (!reg)
+ continue;
+ if (reg->type == SCALAR_VALUE && reg->id == known_reg->id)
+ *reg = *known_reg;
+ }
+ }
+}
+
static int check_cond_jmp_op(struct bpf_verifier_env *env,
struct bpf_insn *insn, int *insn_idx)
{
@@ -7497,6 +7537,11 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
reg_combine_min_max(&other_branch_regs[insn->src_reg],
&other_branch_regs[insn->dst_reg],
src_reg, dst_reg, opcode);
+ if (src_reg->id) {
+ find_equal_scalars(this_branch, src_reg);
+ find_equal_scalars(other_branch, &other_branch_regs[insn->src_reg]);
+ }
+
}
} else if (dst_reg->type == SCALAR_VALUE) {
reg_set_min_max(&other_branch_regs[insn->dst_reg],
@@ -7504,6 +7549,11 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
opcode, is_jmp32);
}
+ if (dst_reg->type == SCALAR_VALUE && dst_reg->id) {
+ find_equal_scalars(this_branch, dst_reg);
+ find_equal_scalars(other_branch, &other_branch_regs[insn->dst_reg]);
+ }
+
/* detect if R == 0 where R is returned from bpf_map_lookup_elem().
* NOTE: these optimizations below are related with pointer comparison
* which will never be JMP32.
@@ -195,13 +195,13 @@ static struct bpf_align_test tests[] = {
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
{7, "R3_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
- {8, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
+ {8, "R4_w=inv(id=1,umax_value=255,var_off=(0x0; 0xff))"},
{9, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
- {10, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
+ {10, "R4_w=inv(id=1,umax_value=255,var_off=(0x0; 0xff))"},
{11, "R4_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"},
- {12, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
+ {12, "R4_w=inv(id=1,umax_value=255,var_off=(0x0; 0xff))"},
{13, "R4_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
- {14, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
+ {14, "R4_w=inv(id=1,umax_value=255,var_off=(0x0; 0xff))"},
{15, "R4_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"},
{16, "R4_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"},
},
@@ -518,7 +518,7 @@ static struct bpf_align_test tests[] = {
* the total offset is 4-byte aligned and meets the
* load's requirements.
*/
- {20, "R5=pkt(id=1,off=0,r=4,umin_value=2,umax_value=1034,var_off=(0x2; 0x7fc)"},
+ {20, "R5=pkt(id=2,off=0,r=4,umin_value=2,umax_value=1034,var_off=(0x2; 0x7fc)"},
},
},
@@ -561,18 +561,18 @@ static struct bpf_align_test tests[] = {
/* Adding 14 makes R6 be (4n+2) */
{11, "R6_w=inv(id=0,umin_value=14,umax_value=74,var_off=(0x2; 0x7c))"},
/* Subtracting from packet pointer overflows ubounds */
- {13, "R5_w=pkt(id=1,off=0,r=8,umin_value=18446744073709551542,umax_value=18446744073709551602,var_off=(0xffffffffffffff82; 0x7c)"},
+ {13, "R5_w=pkt(id=2,off=0,r=8,umin_value=18446744073709551542,umax_value=18446744073709551602,var_off=(0xffffffffffffff82; 0x7c)"},
/* New unknown value in R7 is (4n), >= 76 */
{15, "R7_w=inv(id=0,umin_value=76,umax_value=1096,var_off=(0x0; 0x7fc))"},
/* Adding it to packet pointer gives nice bounds again */
- {16, "R5_w=pkt(id=2,off=0,r=0,umin_value=2,umax_value=1082,var_off=(0x2; 0xfffffffc)"},
+ {16, "R5_w=pkt(id=3,off=0,r=0,umin_value=2,umax_value=1082,var_off=(0x2; 0xfffffffc)"},
/* At the time the word size load is performed from R5,
* its total fixed offset is NET_IP_ALIGN + reg->off (0)
* which is 2. Then the variable offset is (4n+2), so
* the total offset is 4-byte aligned and meets the
* load's requirements.
*/
- {20, "R5=pkt(id=2,off=0,r=4,umin_value=2,umax_value=1082,var_off=(0x2; 0xfffffffc)"},
+ {20, "R5=pkt(id=3,off=0,r=4,umin_value=2,umax_value=1082,var_off=(0x2; 0xfffffffc)"},
},
},
};
@@ -529,7 +529,7 @@
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = REJECT,
- .errstr = "invalid access to packet, off=0 size=8, R5(id=1,off=0,r=0)",
+ .errstr = "invalid access to packet, off=0 size=8, R5(id=2,off=0,r=0)",
.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
},
{