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-rw-r--r--kernel/bpf/verifier.c90
1 files changed, 78 insertions, 12 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 48f3a9acdef3..214a9fa8c6fb 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4549,11 +4549,12 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
state->stack[spi].spilled_ptr.id = 0;
} else if (!reg && !(off % BPF_REG_SIZE) && is_bpf_st_mem(insn) &&
env->bpf_capable) {
- struct bpf_reg_state fake_reg = {};
+ struct bpf_reg_state *tmp_reg = &env->fake_reg[0];
- __mark_reg_known(&fake_reg, insn->imm);
- fake_reg.type = SCALAR_VALUE;
- save_register_state(env, state, spi, &fake_reg, size);
+ memset(tmp_reg, 0, sizeof(*tmp_reg));
+ __mark_reg_known(tmp_reg, insn->imm);
+ tmp_reg->type = SCALAR_VALUE;
+ save_register_state(env, state, spi, tmp_reg, size);
} else if (reg && is_spillable_regtype(reg->type)) {
/* register containing pointer is being spilled into stack */
if (size != BPF_REG_SIZE) {
@@ -6235,6 +6236,7 @@ static void set_sext32_default_val(struct bpf_reg_state *reg, int size)
}
reg->u32_min_value = 0;
reg->u32_max_value = U32_MAX;
+ reg->var_off = tnum_subreg(tnum_unknown);
}
static void coerce_subreg_to_size_sx(struct bpf_reg_state *reg, int size)
@@ -6279,6 +6281,7 @@ static void coerce_subreg_to_size_sx(struct bpf_reg_state *reg, int size)
reg->s32_max_value = s32_max;
reg->u32_min_value = (u32)s32_min;
reg->u32_max_value = (u32)s32_max;
+ reg->var_off = tnum_subreg(tnum_range(s32_min, s32_max));
return;
}
@@ -11128,7 +11131,11 @@ BTF_ID(func, bpf_iter_css_task_new)
#else
BTF_ID_UNUSED
#endif
+#ifdef CONFIG_BPF_EVENTS
BTF_ID(func, bpf_session_cookie)
+#else
+BTF_ID_UNUSED
+#endif
static bool is_kfunc_ret_null(struct bpf_kfunc_call_arg_meta *meta)
{
@@ -12714,6 +12721,16 @@ static bool signed_add32_overflows(s32 a, s32 b)
return res < a;
}
+static bool signed_add16_overflows(s16 a, s16 b)
+{
+ /* Do the add in u16, where overflow is well-defined */
+ s16 res = (s16)((u16)a + (u16)b);
+
+ if (b < 0)
+ return res > a;
+ return res < a;
+}
+
static bool signed_sub_overflows(s64 a, s64 b)
{
/* Do the sub in u64, where overflow is well-defined */
@@ -15109,7 +15126,6 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
struct bpf_reg_state *regs = this_branch->frame[this_branch->curframe]->regs;
struct bpf_reg_state *dst_reg, *other_branch_regs, *src_reg = NULL;
struct bpf_reg_state *eq_branch_regs;
- struct bpf_reg_state fake_reg = {};
u8 opcode = BPF_OP(insn->code);
bool is_jmp32;
int pred = -1;
@@ -15175,7 +15191,8 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
verbose(env, "BPF_JMP/JMP32 uses reserved fields\n");
return -EINVAL;
}
- src_reg = &fake_reg;
+ src_reg = &env->fake_reg[0];
+ memset(src_reg, 0, sizeof(*src_reg));
src_reg->type = SCALAR_VALUE;
__mark_reg_known(src_reg, insn->imm);
}
@@ -15235,10 +15252,16 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
&other_branch_regs[insn->src_reg],
dst_reg, src_reg, opcode, is_jmp32);
} else /* BPF_SRC(insn->code) == BPF_K */ {
+ /* reg_set_min_max() can mangle the fake_reg. Make a copy
+ * so that these are two different memory locations. The
+ * src_reg is not used beyond here in context of K.
+ */
+ memcpy(&env->fake_reg[1], &env->fake_reg[0],
+ sizeof(env->fake_reg[0]));
err = reg_set_min_max(env,
&other_branch_regs[insn->dst_reg],
- src_reg /* fake one */,
- dst_reg, src_reg /* same fake one */,
+ &env->fake_reg[0],
+ dst_reg, &env->fake_reg[1],
opcode, is_jmp32);
}
if (err)
@@ -17437,11 +17460,11 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
goto skip_inf_loop_check;
}
if (is_may_goto_insn_at(env, insn_idx)) {
- if (states_equal(env, &sl->state, cur, RANGE_WITHIN)) {
+ if (sl->state.may_goto_depth != cur->may_goto_depth &&
+ states_equal(env, &sl->state, cur, RANGE_WITHIN)) {
update_loop_entry(cur, &sl->state);
goto hit;
}
- goto skip_inf_loop_check;
}
if (calls_callback(env, insn_idx)) {
if (states_equal(env, &sl->state, cur, RANGE_WITHIN))
@@ -18719,6 +18742,39 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of
return new_prog;
}
+/*
+ * For all jmp insns in a given 'prog' that point to 'tgt_idx' insn adjust the
+ * jump offset by 'delta'.
+ */
+static int adjust_jmp_off(struct bpf_prog *prog, u32 tgt_idx, u32 delta)
+{
+ struct bpf_insn *insn = prog->insnsi;
+ u32 insn_cnt = prog->len, i;
+
+ for (i = 0; i < insn_cnt; i++, insn++) {
+ u8 code = insn->code;
+
+ if ((BPF_CLASS(code) != BPF_JMP && BPF_CLASS(code) != BPF_JMP32) ||
+ BPF_OP(code) == BPF_CALL || BPF_OP(code) == BPF_EXIT)
+ continue;
+
+ if (insn->code == (BPF_JMP32 | BPF_JA)) {
+ if (i + 1 + insn->imm != tgt_idx)
+ continue;
+ if (signed_add32_overflows(insn->imm, delta))
+ return -ERANGE;
+ insn->imm += delta;
+ } else {
+ if (i + 1 + insn->off != tgt_idx)
+ continue;
+ if (signed_add16_overflows(insn->imm, delta))
+ return -ERANGE;
+ insn->off += delta;
+ }
+ }
+ return 0;
+}
+
static int adjust_subprog_starts_after_remove(struct bpf_verifier_env *env,
u32 off, u32 cnt)
{
@@ -19993,7 +20049,10 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
stack_depth_extra = 8;
insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_AX, BPF_REG_10, stack_off);
- insn_buf[1] = BPF_JMP_IMM(BPF_JEQ, BPF_REG_AX, 0, insn->off + 2);
+ if (insn->off >= 0)
+ insn_buf[1] = BPF_JMP_IMM(BPF_JEQ, BPF_REG_AX, 0, insn->off + 2);
+ else
+ insn_buf[1] = BPF_JMP_IMM(BPF_JEQ, BPF_REG_AX, 0, insn->off - 1);
insn_buf[2] = BPF_ALU64_IMM(BPF_SUB, BPF_REG_AX, 1);
insn_buf[3] = BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_AX, stack_off);
cnt = 4;
@@ -20309,7 +20368,7 @@ patch_map_ops_generic:
goto next_insn;
}
-#ifdef CONFIG_X86_64
+#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
/* Implement bpf_get_smp_processor_id() inline. */
if (insn->imm == BPF_FUNC_get_smp_processor_id &&
prog->jit_requested && bpf_jit_supports_percpu_insn()) {
@@ -20535,6 +20594,13 @@ next_insn:
if (!new_prog)
return -ENOMEM;
env->prog = prog = new_prog;
+ /*
+ * If may_goto is a first insn of a prog there could be a jmp
+ * insn that points to it, hence adjust all such jmps to point
+ * to insn after BPF_ST that inits may_goto count.
+ * Adjustment will succeed because bpf_patch_insn_data() didn't fail.
+ */
+ WARN_ON(adjust_jmp_off(env->prog, subprog_start, 1));
}
/* Since poke tab is now finalized, publish aux to tracker. */
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 03:30:35 +0100