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-rw-r--r--kernel/bpf/btf.c5
-rw-r--r--kernel/bpf/core.c8
-rw-r--r--kernel/bpf/helpers.c12
-rw-r--r--kernel/bpf/verifier.c113
4 files changed, 65 insertions, 73 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 63d0ac7dfe2f..eb12d4f705cc 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4815,6 +4815,7 @@ static int btf_check_type_tags(struct btf_verifier_env *env,
n = btf_nr_types(btf);
for (i = start_id; i < n; i++) {
const struct btf_type *t;
+ int chain_limit = 32;
u32 cur_id = i;
t = btf_type_by_id(btf, i);
@@ -4827,6 +4828,10 @@ static int btf_check_type_tags(struct btf_verifier_env *env,
in_tags = btf_type_is_type_tag(t);
while (btf_type_is_modifier(t)) {
+ if (!chain_limit--) {
+ btf_verifier_log(env, "Max chain length or cycle detected");
+ return -ELOOP;
+ }
if (btf_type_is_type_tag(t)) {
if (!in_tags) {
btf_verifier_log(env, "Type tags don't precede modifiers");
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 5f6f3f829b36..e7961508a47d 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -68,11 +68,13 @@ void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, uns
{
u8 *ptr = NULL;
- if (k >= SKF_NET_OFF)
+ if (k >= SKF_NET_OFF) {
ptr = skb_network_header(skb) + k - SKF_NET_OFF;
- else if (k >= SKF_LL_OFF)
+ } else if (k >= SKF_LL_OFF) {
+ if (unlikely(!skb_mac_header_was_set(skb)))
+ return NULL;
ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
-
+ }
if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
return ptr;
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 225806a02efb..bb1254f07667 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1497,11 +1497,12 @@ const struct bpf_func_proto bpf_dynptr_from_mem_proto = {
.arg4_type = ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL | MEM_UNINIT,
};
-BPF_CALL_4(bpf_dynptr_read, void *, dst, u32, len, struct bpf_dynptr_kern *, src, u32, offset)
+BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, struct bpf_dynptr_kern *, src,
+ u32, offset, u64, flags)
{
int err;
- if (!src->data)
+ if (!src->data || flags)
return -EINVAL;
err = bpf_dynptr_check_off_len(src, offset, len);
@@ -1521,13 +1522,15 @@ const struct bpf_func_proto bpf_dynptr_read_proto = {
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_PTR_TO_DYNPTR,
.arg4_type = ARG_ANYTHING,
+ .arg5_type = ARG_ANYTHING,
};
-BPF_CALL_4(bpf_dynptr_write, struct bpf_dynptr_kern *, dst, u32, offset, void *, src, u32, len)
+BPF_CALL_5(bpf_dynptr_write, struct bpf_dynptr_kern *, dst, u32, offset, void *, src,
+ u32, len, u64, flags)
{
int err;
- if (!dst->data || bpf_dynptr_is_rdonly(dst))
+ if (!dst->data || flags || bpf_dynptr_is_rdonly(dst))
return -EINVAL;
err = bpf_dynptr_check_off_len(dst, offset, len);
@@ -1547,6 +1550,7 @@ const struct bpf_func_proto bpf_dynptr_write_proto = {
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE_OR_ZERO,
+ .arg5_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_dynptr_data, struct bpf_dynptr_kern *, ptr, u32, offset, u32, len)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index aedac2ac02b9..0efbac0fd126 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1562,6 +1562,21 @@ static void __reg_bound_offset(struct bpf_reg_state *reg)
reg->var_off = tnum_or(tnum_clear_subreg(var64_off), var32_off);
}
+static void reg_bounds_sync(struct bpf_reg_state *reg)
+{
+ /* We might have learned new bounds from the var_off. */
+ __update_reg_bounds(reg);
+ /* We might have learned something about the sign bit. */
+ __reg_deduce_bounds(reg);
+ /* We might have learned some bits from the bounds. */
+ __reg_bound_offset(reg);
+ /* Intersecting with the old var_off might have improved our bounds
+ * slightly, e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
+ * then new var_off is (0; 0x7f...fc) which improves our umax.
+ */
+ __update_reg_bounds(reg);
+}
+
static bool __reg32_bound_s64(s32 a)
{
return a >= 0 && a <= S32_MAX;
@@ -1603,16 +1618,8 @@ static void __reg_combine_32_into_64(struct bpf_reg_state *reg)
* so they do not impact tnum bounds calculation.
*/
__mark_reg64_unbounded(reg);
- __update_reg_bounds(reg);
}
-
- /* Intersecting with the old var_off might have improved our bounds
- * slightly. e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
- * then new var_off is (0; 0x7f...fc) which improves our umax.
- */
- __reg_deduce_bounds(reg);
- __reg_bound_offset(reg);
- __update_reg_bounds(reg);
+ reg_bounds_sync(reg);
}
static bool __reg64_bound_s32(s64 a)
@@ -1628,7 +1635,6 @@ static bool __reg64_bound_u32(u64 a)
static void __reg_combine_64_into_32(struct bpf_reg_state *reg)
{
__mark_reg32_unbounded(reg);
-
if (__reg64_bound_s32(reg->smin_value) && __reg64_bound_s32(reg->smax_value)) {
reg->s32_min_value = (s32)reg->smin_value;
reg->s32_max_value = (s32)reg->smax_value;
@@ -1637,14 +1643,7 @@ static void __reg_combine_64_into_32(struct bpf_reg_state *reg)
reg->u32_min_value = (u32)reg->umin_value;
reg->u32_max_value = (u32)reg->umax_value;
}
-
- /* Intersecting with the old var_off might have improved our bounds
- * slightly. e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
- * then new var_off is (0; 0x7f...fc) which improves our umax.
- */
- __reg_deduce_bounds(reg);
- __reg_bound_offset(reg);
- __update_reg_bounds(reg);
+ reg_bounds_sync(reg);
}
/* Mark a register as having a completely unknown (scalar) value. */
@@ -6943,9 +6942,7 @@ static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
ret_reg->s32_max_value = meta->msize_max_value;
ret_reg->smin_value = -MAX_ERRNO;
ret_reg->s32_min_value = -MAX_ERRNO;
- __reg_deduce_bounds(ret_reg);
- __reg_bound_offset(ret_reg);
- __update_reg_bounds(ret_reg);
+ reg_bounds_sync(ret_reg);
}
static int
@@ -8202,11 +8199,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
if (!check_reg_sane_offset(env, dst_reg, ptr_reg->type))
return -EINVAL;
-
- __update_reg_bounds(dst_reg);
- __reg_deduce_bounds(dst_reg);
- __reg_bound_offset(dst_reg);
-
+ reg_bounds_sync(dst_reg);
if (sanitize_check_bounds(env, insn, dst_reg) < 0)
return -EACCES;
if (sanitize_needed(opcode)) {
@@ -8944,10 +8937,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
/* ALU32 ops are zero extended into 64bit register */
if (alu32)
zext_32_to_64(dst_reg);
-
- __update_reg_bounds(dst_reg);
- __reg_deduce_bounds(dst_reg);
- __reg_bound_offset(dst_reg);
+ reg_bounds_sync(dst_reg);
return 0;
}
@@ -9136,10 +9126,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
insn->dst_reg);
}
zext_32_to_64(dst_reg);
-
- __update_reg_bounds(dst_reg);
- __reg_deduce_bounds(dst_reg);
- __reg_bound_offset(dst_reg);
+ reg_bounds_sync(dst_reg);
}
} else {
/* case: R = imm
@@ -9577,26 +9564,33 @@ static void reg_set_min_max(struct bpf_reg_state *true_reg,
return;
switch (opcode) {
+ /* JEQ/JNE comparison doesn't change the register equivalence.
+ *
+ * r1 = r2;
+ * if (r1 == 42) goto label;
+ * ...
+ * label: // here both r1 and r2 are known to be 42.
+ *
+ * Hence when marking register as known preserve it's ID.
+ */
case BPF_JEQ:
+ if (is_jmp32) {
+ __mark_reg32_known(true_reg, val32);
+ true_32off = tnum_subreg(true_reg->var_off);
+ } else {
+ ___mark_reg_known(true_reg, val);
+ true_64off = true_reg->var_off;
+ }
+ break;
case BPF_JNE:
- {
- struct bpf_reg_state *reg =
- opcode == BPF_JEQ ? true_reg : false_reg;
-
- /* JEQ/JNE comparison doesn't change the register equivalence.
- * r1 = r2;
- * if (r1 == 42) goto label;
- * ...
- * label: // here both r1 and r2 are known to be 42.
- *
- * Hence when marking register as known preserve it's ID.
- */
- if (is_jmp32)
- __mark_reg32_known(reg, val32);
- else
- ___mark_reg_known(reg, val);
+ if (is_jmp32) {
+ __mark_reg32_known(false_reg, val32);
+ false_32off = tnum_subreg(false_reg->var_off);
+ } else {
+ ___mark_reg_known(false_reg, val);
+ false_64off = false_reg->var_off;
+ }
break;
- }
case BPF_JSET:
if (is_jmp32) {
false_32off = tnum_and(false_32off, tnum_const(~val32));
@@ -9735,21 +9729,8 @@ static void __reg_combine_min_max(struct bpf_reg_state *src_reg,
dst_reg->smax_value);
src_reg->var_off = dst_reg->var_off = tnum_intersect(src_reg->var_off,
dst_reg->var_off);
- /* We might have learned new bounds from the var_off. */
- __update_reg_bounds(src_reg);
- __update_reg_bounds(dst_reg);
- /* We might have learned something about the sign bit. */
- __reg_deduce_bounds(src_reg);
- __reg_deduce_bounds(dst_reg);
- /* We might have learned some bits from the bounds. */
- __reg_bound_offset(src_reg);
- __reg_bound_offset(dst_reg);
- /* Intersecting with the old var_off might have improved our bounds
- * slightly. e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
- * then new var_off is (0; 0x7f...fc) which improves our umax.
- */
- __update_reg_bounds(src_reg);
- __update_reg_bounds(dst_reg);
+ reg_bounds_sync(src_reg);
+ reg_bounds_sync(dst_reg);
}
static void reg_combine_min_max(struct bpf_reg_state *true_src,
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-13 17:50:41 +0300