From: Daniel Borkmann
mainline inclusion
from mainline-v5.13-rc4
commit 3d0220f6861d713213b015b582e9f21e5b28d2e0
category: bugfix
issue: #I421HX
CVE: CVE-2021-33200
--------------------------------
Add a container structure struct bpf_sanitize_info which holds
the current aux info, and update call-sites to sanitize_ptr_alu()
to pass it in. This is needed for passing in additional state
later on.
Signed-off-by: Daniel Borkmann
Reviewed-by: Piotr Krysiuk
Acked-by: Alexei Starovoitov
Signed-off-by: Yang Yingliang
Reviewed-by: Kuohai Xu
Reviewed-by: Xiu Jianfeng
Signed-off-by: Yang Yingliang
Signed-off-by: Yu Changchun
---
kernel/bpf/verifier.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 760b4e316..49c6e125d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2815,15 +2815,19 @@ static bool sanitize_needed(u8 opcode)
return opcode == BPF_ADD || opcode == BPF_SUB;
}
+struct bpf_sanitize_info {
+ struct bpf_insn_aux_data aux;
+};
+
static int sanitize_ptr_alu(struct bpf_verifier_env *env,
struct bpf_insn *insn,
const struct bpf_reg_state *ptr_reg,
const struct bpf_reg_state *off_reg,
struct bpf_reg_state *dst_reg,
- struct bpf_insn_aux_data *tmp_aux,
+ struct bpf_sanitize_info *info,
const bool commit_window)
{
- struct bpf_insn_aux_data *aux = commit_window ? cur_aux(env) : tmp_aux;
+ struct bpf_insn_aux_data *aux = commit_window ? cur_aux(env) : &info->aux;
struct bpf_verifier_state *vstate = env->cur_state;
bool off_is_imm = tnum_is_const(off_reg->var_off);
bool off_is_neg = off_reg->smin_value < 0;
@@ -2852,8 +2856,8 @@ static int sanitize_ptr_alu(struct bpf_verifier_env *env,
/* In commit phase we narrow the masking window based on
* the observed pointer move after the simulated operation.
*/
- alu_state = tmp_aux->alu_state;
- alu_limit = abs(tmp_aux->alu_limit - alu_limit);
+ alu_state = info->aux.alu_state;
+ alu_limit = abs(info->aux.alu_limit - alu_limit);
} else {
alu_state = off_is_neg ? BPF_ALU_NEG_VALUE : 0;
alu_state |= off_is_imm ? BPF_ALU_IMMEDIATE : 0;
@@ -3014,7 +3018,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
smin_ptr = ptr_reg->smin_value, smax_ptr = ptr_reg->smax_value;
u64 umin_val = off_reg->umin_value, umax_val = off_reg->umax_value,
umin_ptr = ptr_reg->umin_value, umax_ptr = ptr_reg->umax_value;
- struct bpf_insn_aux_data tmp_aux = {};
+ struct bpf_sanitize_info info = {};
u8 opcode = BPF_OP(insn->code);
u32 dst = insn->dst_reg;
int ret;
@@ -3066,7 +3070,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
if (sanitize_needed(opcode)) {
ret = sanitize_ptr_alu(env, insn, ptr_reg, off_reg, dst_reg,
- &tmp_aux, false);
+ &info, false);
if (ret < 0)
return sanitize_err(env, insn, ret, off_reg, dst_reg);
}
@@ -3208,7 +3212,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
return -EACCES;
if (sanitize_needed(opcode)) {
ret = sanitize_ptr_alu(env, insn, dst_reg, off_reg, dst_reg,
- &tmp_aux, true);
+ &info, true);
if (ret < 0)
return sanitize_err(env, insn, ret, off_reg, dst_reg);
}
--
2.25.1
