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authorJakub Kicinski2021-06-18 19:47:02 -0700
committerJakub Kicinski2021-06-18 19:47:02 -0700
commitadc2e56ebe6377f5c032d96aee0feac30a640453 (patch)
treef8937ffc72e1991418b0d54a0672766237855c94 /kernel/bpf
parent4bea7207a80c8bba3b3eb5b84c407b162968475f (diff)
parent9ed13a17e38e0537e24d9b507645002bf8d0201f (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Trivial conflicts in net/can/isotp.c and tools/testing/selftests/net/mptcp/mptcp_connect.sh scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c to include/linux/ptp_clock_kernel.h in -next so re-apply the fix there. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/verifier.c68
1 files changed, 61 insertions, 7 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b7d51fc937c7..e04e33893cff 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6485,6 +6485,27 @@ struct bpf_sanitize_info {
bool mask_to_left;
};
+static struct bpf_verifier_state *
+sanitize_speculative_path(struct bpf_verifier_env *env,
+ const struct bpf_insn *insn,
+ u32 next_idx, u32 curr_idx)
+{
+ struct bpf_verifier_state *branch;
+ struct bpf_reg_state *regs;
+
+ branch = push_stack(env, next_idx, curr_idx, true);
+ if (branch && insn) {
+ regs = branch->frame[branch->curframe]->regs;
+ if (BPF_SRC(insn->code) == BPF_K) {
+ mark_reg_unknown(env, regs, insn->dst_reg);
+ } else if (BPF_SRC(insn->code) == BPF_X) {
+ mark_reg_unknown(env, regs, insn->dst_reg);
+ mark_reg_unknown(env, regs, insn->src_reg);
+ }
+ }
+ return branch;
+}
+
static int sanitize_ptr_alu(struct bpf_verifier_env *env,
struct bpf_insn *insn,
const struct bpf_reg_state *ptr_reg,
@@ -6568,12 +6589,26 @@ do_sim:
tmp = *dst_reg;
*dst_reg = *ptr_reg;
}
- ret = push_stack(env, env->insn_idx + 1, env->insn_idx, true);
+ ret = sanitize_speculative_path(env, NULL, env->insn_idx + 1,
+ env->insn_idx);
if (!ptr_is_dst_reg && ret)
*dst_reg = tmp;
return !ret ? REASON_STACK : 0;
}
+static void sanitize_mark_insn_seen(struct bpf_verifier_env *env)
+{
+ struct bpf_verifier_state *vstate = env->cur_state;
+
+ /* If we simulate paths under speculation, we don't update the
+ * insn as 'seen' such that when we verify unreachable paths in
+ * the non-speculative domain, sanitize_dead_code() can still
+ * rewrite/sanitize them.
+ */
+ if (!vstate->speculative)
+ env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+}
+
static int sanitize_err(struct bpf_verifier_env *env,
const struct bpf_insn *insn, int reason,
const struct bpf_reg_state *off_reg,
@@ -8752,14 +8787,28 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
if (err)
return err;
}
+
if (pred == 1) {
- /* only follow the goto, ignore fall-through */
+ /* Only follow the goto, ignore fall-through. If needed, push
+ * the fall-through branch for simulation under speculative
+ * execution.
+ */
+ if (!env->bypass_spec_v1 &&
+ !sanitize_speculative_path(env, insn, *insn_idx + 1,
+ *insn_idx))
+ return -EFAULT;
*insn_idx += insn->off;
return 0;
} else if (pred == 0) {
- /* only follow fall-through branch, since
- * that's where the program will go
+ /* Only follow the fall-through branch, since that's where the
+ * program will go. If needed, push the goto branch for
+ * simulation under speculative execution.
*/
+ if (!env->bypass_spec_v1 &&
+ !sanitize_speculative_path(env, insn,
+ *insn_idx + insn->off + 1,
+ *insn_idx))
+ return -EFAULT;
return 0;
}
@@ -10621,7 +10670,7 @@ static int do_check(struct bpf_verifier_env *env)
}
regs = cur_regs(env);
- env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+ sanitize_mark_insn_seen(env);
prev_insn_idx = env->insn_idx;
if (class == BPF_ALU || class == BPF_ALU64) {
@@ -10848,7 +10897,7 @@ process_bpf_exit:
return err;
env->insn_idx++;
- env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+ sanitize_mark_insn_seen(env);
} else {
verbose(env, "invalid BPF_LD mode\n");
return -EINVAL;
@@ -11381,6 +11430,7 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env,
{
struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data;
struct bpf_insn *insn = new_prog->insnsi;
+ u32 old_seen = old_data[off].seen;
u32 prog_len;
int i;
@@ -11401,7 +11451,8 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env,
memcpy(new_data + off + cnt - 1, old_data + off,
sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1));
for (i = off; i < off + cnt - 1; i++) {
- new_data[i].seen = env->pass_cnt;
+ /* Expand insni[off]'s seen count to the patched range. */
+ new_data[i].seen = old_seen;
new_data[i].zext_dst = insn_has_def32(env, insn + i);
}
env->insn_aux_data = new_data;
@@ -12725,6 +12776,9 @@ static void free_states(struct bpf_verifier_env *env)
* insn_aux_data was touched. These variables are compared to clear temporary
* data from failed pass. For testing and experiments do_check_common() can be
* run multiple times even when prior attempt to verify is unsuccessful.
+ *
+ * Note that special handling is needed on !env->bypass_spec_v1 if this is
+ * ever called outside of error path with subsequent program rejection.
*/
static void sanitize_insn_aux_data(struct bpf_verifier_env *env)
{