Merging upstream version 6.8.12.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 22 insertions, 7 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 11bc3af33f..6edfcc3375 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2328,6 +2328,8 @@ static void mark_btf_ld_reg(struct bpf_verifier_env *env,
 	regs[regno].type = PTR_TO_BTF_ID | flag;
 	regs[regno].btf = btf;
 	regs[regno].btf_id = btf_id;
+	if (type_may_be_null(flag))
+		regs[regno].id = ++env->id_gen;
 }
 
 #define DEF_NOT_SUBREG	(0)
@@ -3584,7 +3586,8 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
 				 * sreg needs precision before this insn
 				 */
 				bt_clear_reg(bt, dreg);
-				bt_set_reg(bt, sreg);
+				if (sreg != BPF_REG_FP)
+					bt_set_reg(bt, sreg);
 			} else {
 				/* dreg = K
 				 * dreg needs precision after this insn.
@@ -3600,7 +3603,8 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
 				 * both dreg and sreg need precision
 				 * before this insn
 				 */
-				bt_set_reg(bt, sreg);
+				if (sreg != BPF_REG_FP)
+					bt_set_reg(bt, sreg);
 			} /* else dreg += K
 			   * dreg still needs precision before this insn
 			   */
@@ -5320,8 +5324,6 @@ static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
 		 */
 		mark_btf_ld_reg(env, cur_regs(env), value_regno, PTR_TO_BTF_ID, kptr_field->kptr.btf,
 				kptr_field->kptr.btf_id, btf_ld_kptr_type(env, kptr_field));
-		/* For mark_ptr_or_null_reg */
-		val_reg->id = ++env->id_gen;
 	} else if (class == BPF_STX) {
 		val_reg = reg_state(env, value_regno);
 		if (!register_is_null(val_reg) &&
@@ -5632,7 +5634,8 @@ static bool is_trusted_reg(const struct bpf_reg_state *reg)
 		return true;
 
 	/* Types listed in the reg2btf_ids are always trusted */
-	if (reg2btf_ids[base_type(reg->type)])
+	if (reg2btf_ids[base_type(reg->type)] &&
+	    !bpf_type_has_unsafe_modifiers(reg->type))
 		return true;
 
 	/* If a register is not referenced, it is trusted if it has the
@@ -6242,6 +6245,7 @@ static int bpf_map_direct_read(struct bpf_map *map, int off, int size, u64 *val,
 #define BTF_TYPE_SAFE_RCU(__type)  __PASTE(__type, __safe_rcu)
 #define BTF_TYPE_SAFE_RCU_OR_NULL(__type)  __PASTE(__type, __safe_rcu_or_null)
 #define BTF_TYPE_SAFE_TRUSTED(__type)  __PASTE(__type, __safe_trusted)
+#define BTF_TYPE_SAFE_TRUSTED_OR_NULL(__type)  __PASTE(__type, __safe_trusted_or_null)
 
 /*
  * Allow list few fields as RCU trusted or full trusted.
@@ -6305,7 +6309,7 @@ BTF_TYPE_SAFE_TRUSTED(struct dentry) {
 	struct inode *d_inode;
 };
 
-BTF_TYPE_SAFE_TRUSTED(struct socket) {
+BTF_TYPE_SAFE_TRUSTED_OR_NULL(struct socket) {
 	struct sock *sk;
 };
 
@@ -6340,11 +6344,20 @@ static bool type_is_trusted(struct bpf_verifier_env *env,
 	BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct linux_binprm));
 	BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct file));
 	BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct dentry));
-	BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct socket));
 
 	return btf_nested_type_is_trusted(&env->log, reg, field_name, btf_id, "__safe_trusted");
 }
 
+static bool type_is_trusted_or_null(struct bpf_verifier_env *env,
+				    struct bpf_reg_state *reg,
+				    const char *field_name, u32 btf_id)
+{
+	BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED_OR_NULL(struct socket));
+
+	return btf_nested_type_is_trusted(&env->log, reg, field_name, btf_id,
+					  "__safe_trusted_or_null");
+}
+
 static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
 				   struct bpf_reg_state *regs,
 				   int regno, int off, int size,
@@ -6453,6 +6466,8 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
 		 */
 		if (type_is_trusted(env, reg, field_name, btf_id)) {
 			flag |= PTR_TRUSTED;
+		} else if (type_is_trusted_or_null(env, reg, field_name, btf_id)) {
+			flag |= PTR_TRUSTED | PTR_MAYBE_NULL;
 		} else if (in_rcu_cs(env) && !type_may_be_null(reg->type)) {
 			if (type_is_rcu(env, reg, field_name, btf_id)) {
 				/* ignore __rcu tag and mark it MEM_RCU */