Merge branch 'emit-endbr-bti-instructions-for-indirect'

Xu Kuohai says:

====================
emit ENDBR/BTI instructions for indirect

On architectures with CFI protection enabled that require landing pad
instructions at indirect jump targets, such as x86 with CET/IBT enabled
and arm64 with BTI enabled, kernel panics when an indirect jump lands on
a target without landing pad. Therefore, the JIT must emit landing pad
instructions for indirect jump targets.

The verifier already recognizes which instructions are indirect jump
targets during the verification phase. So we can store this information
in env->insn_aux_data and pass it to the JIT as new parameter, allowing
the JIT to consult env->insn_aux_data to determine which instructions are
indirect jump targets.

During JIT, constants blinding is performed. It rewrites the private copy
of instructions for the JITed program, but it does not adjust the global
env->insn_aux_data array. As a result, after constants blinding, the
instruction indexes used by JIT may no longer match the indexes in
env->insn_aux_data, so the JIT can not use env->insn_aux_data directly.

To avoid this mismatch, and given that all existing arch-specific JITs
already implement constants blinding with largely duplicated code, move
constants blinding from JIT to generic code.

v15:
- Rebase and target bpf tree
- Resotre subprog_start of the fake 'exit' subprog on failure
- Fix wrong function name used in comment

v14: https://lore.kernel.org/all/cover.1776062885.git.xukuohai@hotmail.com/
- Rebase
- Fix comment style
- Fix incorrect variable and function name used in commit message

v13: https://lore.kernel.org/bpf/20260411133847.1042658-1-xukuohai@huaweicloud.com
- Use vmalloc to allocate memory for insn_aux_data copies to match with vfree
- Do not free the copied memory of insn_aux_data when restoring from failure
- Code cleanup

v12: https://lore.kernel.org/bpf/20260403132811.753894-1-xukuohai@huaweicloud.com
- Restore env->insn_aux_data on JIT failure
- Fix incorrect error code sign (-EFAULT vs EFAULT)
- Fix incorrect prog used in the restore path

v11: https://lore.kernel.org/bpf/20260403090915.473493-1-xukuohai@huaweicloud.com
- Restore env->subprog_info after jit_subprogs() fails
- Clear prog->jit_requested and prog->blinding_requested on failure
- Use the actual env->insn_aux_data size in clear_insn_aux_data() on failure

v10: https://lore.kernel.org/bpf/20260324122052.342751-1-xukuohai@huaweicloud.com
- Fix the incorrect call_imm restore in jit_subprogs
- Define a dummy void version of bpf_jit_prog_release_other and
  bpf_patch_insn_data when the corresponding config is not set
- Remove the unnecessary #ifdef in x86_64 JIT (Leon Hwang)

v9: https://lore.kernel.org/bpf/20260312170255.3427799-1-xukuohai@huaweicloud.com
- Make constant blinding available for classic bpf (Eduard)
- Clear prog->bpf_func, prog->jited ... on the error path of extra pass (Eduard)
- Fix spelling errors and remove unused parameter (Anton Protopopov)

v8: https://lore.kernel.org/bpf/20260309140044.2652538-1-xukuohai@huaweicloud.com
- Define void bpf_jit_blind_constants() function when CONFIG_BPF_JIT is not set
- Move indirect_target fixup for insn patching from bpf_jit_blind_constants()
  to adjust_insn_aux_data()

v7: https://lore.kernel.org/bpf/20260307103949.2340104-1-xukuohai@huaweicloud.com
- Move constants blinding logic back to bpf/core.c
- Compute ip address before switch statement in x86 JIT
- Clear JIT state from error path on arm64 and loongarch

v6: https://lore.kernel.org/bpf/20260306102329.2056216-1-xukuohai@huaweicloud.com
- Move constants blinding from JIT to verifier
- Move call to bpf_prog_select_runtime from bpf_prog_load to verifier

v5: https://lore.kernel.org/bpf/20260302102726.1126019-1-xukuohai@huaweicloud.com
- Switch to pass env to JIT directly to get rid of copying private insn_aux_data for
  each prog

v4: https://lore.kernel.org/all/20260114093914.2403982-1-xukuohai@huaweicloud.com
- Switch to the approach proposed by Eduard, using insn_aux_data to identify indirect
  jump targets, and emit ENDBR on x86

v3: https://lore.kernel.org/bpf/20251227081033.240336-1-xukuohai@huaweicloud.com
- Get rid of unnecessary enum definition (Yonghong Song, Anton Protopopov)

v2: https://lore.kernel.org/bpf/20251223085447.139301-1-xukuohai@huaweicloud.com
- Exclude instruction arrays not used for indirect jumps (Anton Protopopov)

v1: https://lore.kernel.org/bpf/20251127140318.3944249-1-xukuohai@huaweicloud.com
====================

Link: https://patch.msgid.link/20260416064341.151802-1-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

4 files changed, 251 insertions, 74 deletions

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 066b86e7233c..8b018ff48875 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1491,24 +1491,11 @@ void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
 	bpf_prog_clone_free(fp_other);
 }
 
-static void adjust_insn_arrays(struct bpf_prog *prog, u32 off, u32 len)
-{
-#ifdef CONFIG_BPF_SYSCALL
-	struct bpf_map *map;
-	int i;
-
-	if (len <= 1)
-		return;
-
-	for (i = 0; i < prog->aux->used_map_cnt; i++) {
-		map = prog->aux->used_maps[i];
-		if (map->map_type == BPF_MAP_TYPE_INSN_ARRAY)
-			bpf_insn_array_adjust(map, off, len);
-	}
-#endif
-}
-
-struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
+/*
+ * Now this function is used only to blind the main prog and must be invoked only when
+ * bpf_prog_need_blind() returns true.
+ */
+struct bpf_prog *bpf_jit_blind_constants(struct bpf_verifier_env *env, struct bpf_prog *prog)
 {
 	struct bpf_insn insn_buff[16], aux[2];
 	struct bpf_prog *clone, *tmp;
@@ -1516,13 +1503,17 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
 	struct bpf_insn *insn;
 	int i, rewritten;
 
-	if (!prog->blinding_requested || prog->blinded)
-		return prog;
+	if (WARN_ON_ONCE(env && env->prog != prog))
+		return ERR_PTR(-EINVAL);
 
 	clone = bpf_prog_clone_create(prog, GFP_USER);
 	if (!clone)
 		return ERR_PTR(-ENOMEM);
 
+	/* make sure bpf_patch_insn_data() patches the correct prog */
+	if (env)
+		env->prog = clone;
+
 	insn_cnt = clone->len;
 	insn = clone->insnsi;
 
@@ -1550,21 +1541,28 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
 		if (!rewritten)
 			continue;
 
-		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
-		if (IS_ERR(tmp)) {
+		if (env)
+			tmp = bpf_patch_insn_data(env, i, insn_buff, rewritten);
+		else
+			tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
+
+		if (IS_ERR_OR_NULL(tmp)) {
+			if (env)
+				/* restore the original prog */
+				env->prog = prog;
 			/* Patching may have repointed aux->prog during
 			 * realloc from the original one, so we need to
 			 * fix it up here on error.
 			 */
 			bpf_jit_prog_release_other(prog, clone);
-			return tmp;
+			return IS_ERR(tmp) ? tmp : ERR_PTR(-ENOMEM);
 		}
 
 		clone = tmp;
 		insn_delta = rewritten - 1;
 
-		/* Instructions arrays must be updated using absolute xlated offsets */
-		adjust_insn_arrays(clone, prog->aux->subprog_start + i, rewritten);
+		if (env)
+			env->prog = clone;
 
 		/* Walk new program and skip insns we just inserted. */
 		insn = clone->insnsi + i + insn_delta;
@@ -1575,6 +1573,15 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
 	clone->blinded = 1;
 	return clone;
 }
+
+bool bpf_insn_is_indirect_target(const struct bpf_verifier_env *env, const struct bpf_prog *prog,
+				 int insn_idx)
+{
+	if (!env)
+		return false;
+	insn_idx += prog->aux->subprog_start;
+	return env->insn_aux_data[insn_idx].indirect_target;
+}
 #endif /* CONFIG_BPF_JIT */
 
 /* Base function for offset calculation. Needs to go into .text section,
@@ -2533,18 +2540,55 @@ static bool bpf_prog_select_interpreter(struct bpf_prog *fp)
 	return select_interpreter;
 }
 
-/**
- *	bpf_prog_select_runtime - select exec runtime for BPF program
- *	@fp: bpf_prog populated with BPF program
- *	@err: pointer to error variable
- *
- * Try to JIT eBPF program, if JIT is not available, use interpreter.
- * The BPF program will be executed via bpf_prog_run() function.
- *
- * Return: the &fp argument along with &err set to 0 for success or
- * a negative errno code on failure
- */
-struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
+static struct bpf_prog *bpf_prog_jit_compile(struct bpf_verifier_env *env, struct bpf_prog *prog)
+{
+#ifdef CONFIG_BPF_JIT
+	struct bpf_prog *orig_prog;
+	struct bpf_insn_aux_data *orig_insn_aux;
+
+	if (!bpf_prog_need_blind(prog))
+		return bpf_int_jit_compile(env, prog);
+
+	if (env) {
+		/*
+		 * If env is not NULL, we are called from the end of bpf_check(), at this
+		 * point, only insn_aux_data is used after failure, so it should be restored
+		 * on failure.
+		 */
+		orig_insn_aux = bpf_dup_insn_aux_data(env);
+		if (!orig_insn_aux)
+			return prog;
+	}
+
+	orig_prog = prog;
+	prog = bpf_jit_blind_constants(env, prog);
+	/*
+	 * If blinding was requested and we failed during blinding, we must fall
+	 * back to the interpreter.
+	 */
+	if (IS_ERR(prog))
+		goto out_restore;
+
+	prog = bpf_int_jit_compile(env, prog);
+	if (prog->jited) {
+		bpf_jit_prog_release_other(prog, orig_prog);
+		if (env)
+			vfree(orig_insn_aux);
+		return prog;
+	}
+
+	bpf_jit_prog_release_other(orig_prog, prog);
+
+out_restore:
+	prog = orig_prog;
+	if (env)
+		bpf_restore_insn_aux_data(env, orig_insn_aux);
+#endif
+	return prog;
+}
+
+struct bpf_prog *__bpf_prog_select_runtime(struct bpf_verifier_env *env, struct bpf_prog *fp,
+					   int *err)
 {
 	/* In case of BPF to BPF calls, verifier did all the prep
 	 * work with regards to JITing, etc.
@@ -2572,7 +2616,7 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
 		if (*err)
 			return fp;
 
-		fp = bpf_int_jit_compile(fp);
+		fp = bpf_prog_jit_compile(env, fp);
 		bpf_prog_jit_attempt_done(fp);
 		if (!fp->jited && jit_needed) {
 			*err = -ENOTSUPP;
@@ -2598,6 +2642,22 @@ finalize:
 
 	return fp;
 }
+
+/**
+ *	bpf_prog_select_runtime - select exec runtime for BPF program
+ *	@fp: bpf_prog populated with BPF program
+ *	@err: pointer to error variable
+ *
+ * Try to JIT eBPF program, if JIT is not available, use interpreter.
+ * The BPF program will be executed via bpf_prog_run() function.
+ *
+ * Return: the &fp argument along with &err set to 0 for success or
+ * a negative errno code on failure
+ */
+struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
+{
+	return __bpf_prog_select_runtime(NULL, fp, err);
+}
 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
 
 static unsigned int __bpf_prog_ret1(const void *ctx,
@@ -3085,7 +3145,7 @@ const struct bpf_func_proto bpf_tail_call_proto = {
  * It is encouraged to implement bpf_int_jit_compile() instead, so that
  * eBPF and implicitly also cBPF can get JITed!
  */
-struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
+struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_verifier_env *env, struct bpf_prog *prog)
 {
 	return prog;
 }
diff --git a/kernel/bpf/fixups.c b/kernel/bpf/fixups.c
index dd00a680e4ea..fba9e8c00878 100644
--- a/kernel/bpf/fixups.c
+++ b/kernel/bpf/fixups.c
@@ -183,6 +183,18 @@ static void adjust_insn_aux_data(struct bpf_verifier_env *env,
 		data[i].seen = old_seen;
 		data[i].zext_dst = insn_has_def32(insn + i);
 	}
+
+	/*
+	 * The indirect_target flag of the original instruction was moved to the last of the
+	 * new instructions by the above memmove and memset, but the indirect jump target is
+	 * actually the first instruction, so move it back. This also matches with the behavior
+	 * of bpf_insn_array_adjust(), which preserves xlated_off to point to the first new
+	 * instruction.
+	 */
+	if (data[off + cnt - 1].indirect_target) {
+		data[off].indirect_target = 1;
+		data[off + cnt - 1].indirect_target = 0;
+	}
 }
 
 static void adjust_subprog_starts(struct bpf_verifier_env *env, u32 off, u32 len)
@@ -232,8 +244,8 @@ static void adjust_poke_descs(struct bpf_prog *prog, u32 off, u32 len)
 	}
 }
 
-static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 off,
-					    const struct bpf_insn *patch, u32 len)
+struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 off,
+				     const struct bpf_insn *patch, u32 len)
 {
 	struct bpf_prog *new_prog;
 	struct bpf_insn_aux_data *new_data = NULL;
@@ -973,7 +985,47 @@ patch_insn_buf:
 	return 0;
 }
 
-int bpf_jit_subprogs(struct bpf_verifier_env *env)
+static u32 *bpf_dup_subprog_starts(struct bpf_verifier_env *env)
+{
+	u32 *starts = NULL;
+
+	starts = kvmalloc_objs(u32, env->subprog_cnt, GFP_KERNEL_ACCOUNT);
+	if (starts) {
+		for (int i = 0; i < env->subprog_cnt; i++)
+			starts[i] = env->subprog_info[i].start;
+	}
+	return starts;
+}
+
+static void bpf_restore_subprog_starts(struct bpf_verifier_env *env, u32 *orig_starts)
+{
+	for (int i = 0; i < env->subprog_cnt; i++)
+		env->subprog_info[i].start = orig_starts[i];
+	/* restore the start of fake 'exit' subprog as well */
+	env->subprog_info[env->subprog_cnt].start = env->prog->len;
+}
+
+struct bpf_insn_aux_data *bpf_dup_insn_aux_data(struct bpf_verifier_env *env)
+{
+	size_t size;
+	void *new_aux;
+
+	size = array_size(sizeof(struct bpf_insn_aux_data), env->prog->len);
+	new_aux = __vmalloc(size, GFP_KERNEL_ACCOUNT);
+	if (new_aux)
+		memcpy(new_aux, env->insn_aux_data, size);
+	return new_aux;
+}
+
+void bpf_restore_insn_aux_data(struct bpf_verifier_env *env,
+			       struct bpf_insn_aux_data *orig_insn_aux)
+{
+	/* the expanded elements are zero-filled, so no special handling is required */
+	vfree(env->insn_aux_data);
+	env->insn_aux_data = orig_insn_aux;
+}
+
+static int jit_subprogs(struct bpf_verifier_env *env)
 {
 	struct bpf_prog *prog = env->prog, **func, *tmp;
 	int i, j, subprog_start, subprog_end = 0, len, subprog;
@@ -981,10 +1033,6 @@ int bpf_jit_subprogs(struct bpf_verifier_env *env)
 	struct bpf_insn *insn;
 	void *old_bpf_func;
 	int err, num_exentries;
-	int old_len, subprog_start_adjustment = 0;
-
-	if (env->subprog_cnt <= 1)
-		return 0;
 
 	for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
 		if (!bpf_pseudo_func(insn) && !bpf_pseudo_call(insn))
@@ -1053,10 +1101,11 @@ int bpf_jit_subprogs(struct bpf_verifier_env *env)
 			goto out_free;
 		func[i]->is_func = 1;
 		func[i]->sleepable = prog->sleepable;
+		func[i]->blinded = prog->blinded;
 		func[i]->aux->func_idx = i;
 		/* Below members will be freed only at prog->aux */
 		func[i]->aux->btf = prog->aux->btf;
-		func[i]->aux->subprog_start = subprog_start + subprog_start_adjustment;
+		func[i]->aux->subprog_start = subprog_start;
 		func[i]->aux->func_info = prog->aux->func_info;
 		func[i]->aux->func_info_cnt = prog->aux->func_info_cnt;
 		func[i]->aux->poke_tab = prog->aux->poke_tab;
@@ -1113,15 +1162,7 @@ int bpf_jit_subprogs(struct bpf_verifier_env *env)
 		func[i]->aux->token = prog->aux->token;
 		if (!i)
 			func[i]->aux->exception_boundary = env->seen_exception;
-
-		/*
-		 * To properly pass the absolute subprog start to jit
-		 * all instruction adjustments should be accumulated
-		 */
-		old_len = func[i]->len;
-		func[i] = bpf_int_jit_compile(func[i]);
-		subprog_start_adjustment += func[i]->len - old_len;
-
+		func[i] = bpf_int_jit_compile(env, func[i]);
 		if (!func[i]->jited) {
 			err = -ENOTSUPP;
 			goto out_free;
@@ -1165,7 +1206,7 @@ int bpf_jit_subprogs(struct bpf_verifier_env *env)
 	}
 	for (i = 0; i < env->subprog_cnt; i++) {
 		old_bpf_func = func[i]->bpf_func;
-		tmp = bpf_int_jit_compile(func[i]);
+		tmp = bpf_int_jit_compile(env, func[i]);
 		if (tmp != func[i] || func[i]->bpf_func != old_bpf_func) {
 			verbose(env, "JIT doesn't support bpf-to-bpf calls\n");
 			err = -ENOTSUPP;
@@ -1247,16 +1288,87 @@ out_free:
 	}
 	kfree(func);
 out_undo_insn:
+	bpf_prog_jit_attempt_done(prog);
+	return err;
+}
+
+int bpf_jit_subprogs(struct bpf_verifier_env *env)
+{
+	int err, i;
+	bool blinded = false;
+	struct bpf_insn *insn;
+	struct bpf_prog *prog, *orig_prog;
+	struct bpf_insn_aux_data *orig_insn_aux;
+	u32 *orig_subprog_starts;
+
+	if (env->subprog_cnt <= 1)
+		return 0;
+
+	prog = orig_prog = env->prog;
+	if (bpf_prog_need_blind(prog)) {
+		orig_insn_aux = bpf_dup_insn_aux_data(env);
+		if (!orig_insn_aux) {
+			err = -ENOMEM;
+			goto out_cleanup;
+		}
+		orig_subprog_starts = bpf_dup_subprog_starts(env);
+		if (!orig_subprog_starts) {
+			vfree(orig_insn_aux);
+			err = -ENOMEM;
+			goto out_cleanup;
+		}
+		prog = bpf_jit_blind_constants(env, prog);
+		if (IS_ERR(prog)) {
+			err = -ENOMEM;
+			prog = orig_prog;
+			goto out_restore;
+		}
+		blinded = true;
+	}
+
+	err = jit_subprogs(env);
+	if (err)
+		goto out_jit_err;
+
+	if (blinded) {
+		bpf_jit_prog_release_other(prog, orig_prog);
+		kvfree(orig_subprog_starts);
+		vfree(orig_insn_aux);
+	}
+
+	return 0;
+
+out_jit_err:
+	if (blinded) {
+		bpf_jit_prog_release_other(orig_prog, prog);
+		/* roll back to the clean original prog */
+		prog = env->prog = orig_prog;
+		goto out_restore;
+	} else {
+		if (err != -EFAULT) {
+			/*
+			 * We will fall back to interpreter mode when err is not -EFAULT, before
+			 * that, insn->off and insn->imm should be restored to their original
+			 * values since they were modified by jit_subprogs.
+			 */
+			for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
+				if (!bpf_pseudo_call(insn))
+					continue;
+				insn->off = 0;
+				insn->imm = env->insn_aux_data[i].call_imm;
+			}
+		}
+		goto out_cleanup;
+	}
+
+out_restore:
+	bpf_restore_subprog_starts(env, orig_subprog_starts);
+	bpf_restore_insn_aux_data(env, orig_insn_aux);
+	kvfree(orig_subprog_starts);
+out_cleanup:
 	/* cleanup main prog to be interpreted */
 	prog->jit_requested = 0;
 	prog->blinding_requested = 0;
-	for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
-		if (!bpf_pseudo_call(insn))
-			continue;
-		insn->off = 0;
-		insn->imm = env->insn_aux_data[i].call_imm;
-	}
-	bpf_prog_jit_attempt_done(prog);
 	return err;
 }
 
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index b73b25c63073..a3c0214ca934 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3083,10 +3083,6 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 	if (err < 0)
 		goto free_used_maps;
 
-	prog = bpf_prog_select_runtime(prog, &err);
-	if (err < 0)
-		goto free_used_maps;
-
 	err = bpf_prog_mark_insn_arrays_ready(prog);
 	if (err < 0)
 		goto free_used_maps;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 9e4980128151..1e36b9e91277 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3497,6 +3497,11 @@ static int insn_stack_access_flags(int frameno, int spi)
 	return INSN_F_STACK_ACCESS | (spi << INSN_F_SPI_SHIFT) | frameno;
 }
 
+static void mark_indirect_target(struct bpf_verifier_env *env, int idx)
+{
+	env->insn_aux_data[idx].indirect_target = true;
+}
+
 #define LR_FRAMENO_BITS	3
 #define LR_SPI_BITS	6
 #define LR_ENTRY_BITS	(LR_SPI_BITS + LR_FRAMENO_BITS + 1)
@@ -17545,12 +17550,14 @@ static int check_indirect_jump(struct bpf_verifier_env *env, struct bpf_insn *in
 	}
 
 	for (i = 0; i < n - 1; i++) {
+		mark_indirect_target(env, env->gotox_tmp_buf->items[i]);
 		other_branch = push_stack(env, env->gotox_tmp_buf->items[i],
 					  env->insn_idx, env->cur_state->speculative);
 		if (IS_ERR(other_branch))
 			return PTR_ERR(other_branch);
 	}
 	env->insn_idx = env->gotox_tmp_buf->items[n-1];
+	mark_indirect_target(env, env->insn_idx);
 	return INSN_IDX_UPDATED;
 }
 
@@ -20155,6 +20162,14 @@ skip_full_check:
 
 	adjust_btf_func(env);
 
+	/* extension progs temporarily inherit the attach_type of their targets
+	   for verification purposes, so set it back to zero before returning
+	 */
+	if (env->prog->type == BPF_PROG_TYPE_EXT)
+		env->prog->expected_attach_type = 0;
+
+	env->prog = __bpf_prog_select_runtime(env, env->prog, &ret);
+
 err_release_maps:
 	if (ret)
 		release_insn_arrays(env);
@@ -20166,12 +20181,6 @@ err_release_maps:
 	if (!env->prog->aux->used_btfs)
 		release_btfs(env);
 
-	/* extension progs temporarily inherit the attach_type of their targets
-	   for verification purposes, so set it back to zero before returning
-	 */
-	if (env->prog->type == BPF_PROG_TYPE_EXT)
-		env->prog->expected_attach_type = 0;
-
 	*prog = env->prog;
 
 	module_put(env->attach_btf_mod);