FAILED: patch "[PATCH] bpf: Keep dynamic inner array lookups nullable" failed to apply to 6.18-stable tree

FAILED: patch "[PATCH] bpf: Keep dynamic inner array lookups nullable" failed to apply to 6.18-stable tree

[gregkh]

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 53040a81ae57cdca8af8ac36fe4e661730cf7c6b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026071438-pester-imperial-a2dc@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 53040a81ae57cdca8af8ac36fe4e661730cf7c6b Mon Sep 17 00:00:00 2001
From: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
Date: Sun, 7 Jun 2026 21:24:13 +0800
Subject: [PATCH] bpf: Keep dynamic inner array lookups nullable

An ARRAY_OF_MAPS can use an array created with BPF_F_INNER_MAP as its
inner map template. A concrete inner array with a different max_entries
value can then replace the template.

After a successful outer map lookup, the verifier represents the
resulting map pointer using the inner map template. Const-key lookup
nullness elision consequently uses the template max_entries even though
the runtime helper uses the concrete inner map max_entries.

Do not elide lookup result nullness for maps marked with BPF_F_INNER_MAP,
because the template max_entries does not prove that the key is in bounds
for the concrete runtime map.

Fixes: d2102f2f5d75 ("bpf: verifier: Support eliding map lookup nullness")
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20260607-f01-v2-v2-1-da48453146e8@mails.tsinghua.edu.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 0c1cf506c219..ed7ba0e6a9ce 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -8179,7 +8179,7 @@ static int get_constant_map_key(struct bpf_verifier_env *env,
 	return 0;
 }
 
-static bool can_elide_value_nullness(enum bpf_map_type type);
+static bool can_elide_value_nullness(const struct bpf_map *map);
 
 static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 			  struct bpf_call_arg_meta *meta,
@@ -8298,7 +8298,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 		err = check_helper_mem_access(env, reg, argno_from_reg(regno), key_size, BPF_READ, false, NULL);
 		if (err)
 			return err;
-		if (can_elide_value_nullness(meta->map.ptr->map_type)) {
+		if (can_elide_value_nullness(meta->map.ptr)) {
 			err = get_constant_map_key(env, reg, key_size, &meta->const_map_key);
 			if (err < 0) {
 				meta->const_map_key = -1;
@@ -10068,13 +10068,16 @@ static void update_loop_inline_state(struct bpf_verifier_env *env, u32 subprogno
 				 state->callback_subprogno == subprogno);
 }
 
-/* Returns whether or not the given map type can potentially elide
+/* Returns whether or not the given map can potentially elide
  * lookup return value nullness check. This is possible if the key
  * is statically known.
  */
-static bool can_elide_value_nullness(enum bpf_map_type type)
+static bool can_elide_value_nullness(const struct bpf_map *map)
 {
-	switch (type) {
+	if (map->map_flags & BPF_F_INNER_MAP)
+		return false;
+
+	switch (map->map_type) {
 	case BPF_MAP_TYPE_ARRAY:
 	case BPF_MAP_TYPE_PERCPU_ARRAY:
 		return true;
@@ -10414,7 +10417,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 		}
 
 		if (func_id == BPF_FUNC_map_lookup_elem &&
-		    can_elide_value_nullness(meta.map.ptr->map_type) &&
+		    can_elide_value_nullness(meta.map.ptr) &&
 		    meta.const_map_key >= 0 &&
 		    meta.const_map_key < meta.map.ptr->max_entries)
 			ret_flag &= ~PTR_MAYBE_NULL;

[PATCH 6.18.y 1/3] bpf: Consistently use reg_state() for register access in the verifier

[Sasha Levin]

From: Mykyta Yatsenko <yatsenko@meta.com>

[ Upstream commit 7af3339948601e188d93d7e03326aeb8fcbd6bea ]

Replace the pattern of declaring a local regs array from cur_regs()
and then indexing into it with the more concise reg_state() helper.
This simplifies the code by eliminating intermediate variables and
makes register access more consistent throughout the verifier.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20260113134826.2214860-1-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 53040a81ae57 ("bpf: Keep dynamic inner array lookups nullable")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/bpf/verifier.c | 42 +++++++++++++++++++-----------------------
 1 file changed, 19 insertions(+), 23 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 3dcf591acd50d2..90f3cf19849fdc 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5686,8 +5686,8 @@ static int check_stack_write(struct bpf_verifier_env *env,
 static int check_map_access_type(struct bpf_verifier_env *env, u32 regno,
 				 int off, int size, enum bpf_access_type type)
 {
-	struct bpf_reg_state *regs = cur_regs(env);
-	struct bpf_map *map = regs[regno].map_ptr;
+	struct bpf_reg_state *reg = reg_state(env, regno);
+	struct bpf_map *map = reg->map_ptr;
 	u32 cap = bpf_map_flags_to_cap(map);
 
 	if (type == BPF_WRITE && !(cap & BPF_MAP_CAN_WRITE)) {
@@ -6191,8 +6191,7 @@ static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
 static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off,
 			       int size, bool zero_size_allowed)
 {
-	struct bpf_reg_state *regs = cur_regs(env);
-	struct bpf_reg_state *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	int err;
 
 	/* We may have added a variable offset to the packet pointer; but any
@@ -6279,8 +6278,7 @@ static int check_sock_access(struct bpf_verifier_env *env, int insn_idx,
 			     u32 regno, int off, int size,
 			     enum bpf_access_type t)
 {
-	struct bpf_reg_state *regs = cur_regs(env);
-	struct bpf_reg_state *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct bpf_insn_access_aux info = {};
 	bool valid;
 
@@ -7465,8 +7463,7 @@ static int check_stack_access_within_bounds(
 		int regno, int off, int access_size,
 		enum bpf_access_type type)
 {
-	struct bpf_reg_state *regs = cur_regs(env);
-	struct bpf_reg_state *reg = regs + regno;
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct bpf_func_state *state = func(env, reg);
 	s64 min_off, max_off;
 	int err;
@@ -8409,7 +8406,7 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, int flags)
 {
 	bool is_lock = flags & PROCESS_SPIN_LOCK, is_res_lock = flags & PROCESS_RES_LOCK;
 	const char *lock_str = is_res_lock ? "bpf_res_spin" : "bpf_spin";
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct bpf_verifier_state *cur = env->cur_state;
 	bool is_const = tnum_is_const(reg->var_off);
 	bool is_irq = flags & PROCESS_LOCK_IRQ;
@@ -8525,7 +8522,7 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, int flags)
 static int check_map_field_pointer(struct bpf_verifier_env *env, u32 regno,
 				   enum btf_field_type field_type)
 {
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	bool is_const = tnum_is_const(reg->var_off);
 	struct bpf_map *map = reg->map_ptr;
 	u64 val = reg->var_off.value;
@@ -8572,7 +8569,7 @@ static int check_map_field_pointer(struct bpf_verifier_env *env, u32 regno,
 static int process_timer_func(struct bpf_verifier_env *env, int regno,
 			      struct bpf_call_arg_meta *meta)
 {
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct bpf_map *map = reg->map_ptr;
 	int err;
 
@@ -8596,7 +8593,7 @@ static int process_timer_func(struct bpf_verifier_env *env, int regno,
 static int process_wq_func(struct bpf_verifier_env *env, int regno,
 			   struct bpf_kfunc_call_arg_meta *meta)
 {
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct bpf_map *map = reg->map_ptr;
 	int err;
 
@@ -8617,7 +8614,7 @@ static int process_wq_func(struct bpf_verifier_env *env, int regno,
 static int process_task_work_func(struct bpf_verifier_env *env, int regno,
 				  struct bpf_kfunc_call_arg_meta *meta)
 {
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct bpf_map *map = reg->map_ptr;
 	int err;
 
@@ -8637,7 +8634,7 @@ static int process_task_work_func(struct bpf_verifier_env *env, int regno,
 static int process_kptr_func(struct bpf_verifier_env *env, int regno,
 			     struct bpf_call_arg_meta *meta)
 {
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct btf_field *kptr_field;
 	struct bpf_map *map_ptr;
 	struct btf_record *rec;
@@ -8710,7 +8707,7 @@ static int process_kptr_func(struct bpf_verifier_env *env, int regno,
 static int process_dynptr_func(struct bpf_verifier_env *env, int regno, int insn_idx,
 			       enum bpf_arg_type arg_type, int clone_ref_obj_id)
 {
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	int err;
 
 	if (reg->type != PTR_TO_STACK && reg->type != CONST_PTR_TO_DYNPTR) {
@@ -8830,7 +8827,7 @@ static bool is_kfunc_arg_iter(struct bpf_kfunc_call_arg_meta *meta, int arg_idx,
 static int process_iter_arg(struct bpf_verifier_env *env, int regno, int insn_idx,
 			    struct bpf_kfunc_call_arg_meta *meta)
 {
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	const struct btf_type *t;
 	int spi, err, i, nr_slots, btf_id;
 
@@ -9302,7 +9299,7 @@ static int check_reg_type(struct bpf_verifier_env *env, u32 regno,
 			  const u32 *arg_btf_id,
 			  struct bpf_call_arg_meta *meta)
 {
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	enum bpf_reg_type expected, type = reg->type;
 	const struct bpf_reg_types *compatible;
 	int i, j;
@@ -9715,7 +9712,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 			  int insn_idx)
 {
 	u32 regno = BPF_REG_1 + arg;
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	enum bpf_arg_type arg_type = fn->arg_type[arg];
 	enum bpf_reg_type type = reg->type;
 	u32 *arg_btf_id = NULL;
@@ -11245,7 +11242,7 @@ record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
 		int func_id, int insn_idx)
 {
 	struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
-	struct bpf_reg_state *regs = cur_regs(env), *reg;
+	struct bpf_reg_state *reg;
 	struct bpf_map *map = meta->map_ptr;
 	u64 val, max;
 	int err;
@@ -11257,7 +11254,7 @@ record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
 		return -EINVAL;
 	}
 
-	reg = &regs[BPF_REG_3];
+	reg = reg_state(env, BPF_REG_3);
 	val = reg->var_off.value;
 	max = map->max_entries;
 
@@ -11403,8 +11400,7 @@ static struct bpf_insn_aux_data *cur_aux(const struct bpf_verifier_env *env)
 
 static bool loop_flag_is_zero(struct bpf_verifier_env *env)
 {
-	struct bpf_reg_state *regs = cur_regs(env);
-	struct bpf_reg_state *reg = &regs[BPF_REG_4];
+	struct bpf_reg_state *reg = reg_state(env, BPF_REG_4);
 	bool reg_is_null = register_is_null(reg);
 
 	if (reg_is_null)
@@ -12675,7 +12671,7 @@ static int process_kf_arg_ptr_to_btf_id(struct bpf_verifier_env *env,
 static int process_irq_flag(struct bpf_verifier_env *env, int regno,
 			     struct bpf_kfunc_call_arg_meta *meta)
 {
-	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_reg_state *reg = reg_state(env, regno);
 	int err, kfunc_class = IRQ_NATIVE_KFUNC;
 	bool irq_save;
 
-- 
2.53.0

[PATCH 6.18.y 2/3] bpf: Introduce struct bpf_map_desc in verifier

[Sasha Levin]

From: Mykyta Yatsenko <yatsenko@meta.com>

[ Upstream commit 98c4fd2963cb2bc5eae22b5365e6bbf3a5cd0f14 ]

Introduce struct bpf_map_desc to hold bpf_map pointer and map uid. Use
this struct in both bpf_call_arg_meta and bpf_kfunc_call_arg_meta
instead of having different representations:
 - bpf_call_arg_meta had separate map_ptr and map_uid fields
 - bpf_kfunc_call_arg_meta had an anonymous inline struct

This unifies the map fields layout across both metadata structures,
making the code more consistent and preparing for further refactoring of
map field pointer validation.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260130-verif_special_fields-v2-1-2c59e637da7d@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 53040a81ae57 ("bpf: Keep dynamic inner array lookups nullable")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/bpf/verifier.c | 79 ++++++++++++++++++++++---------------------
 1 file changed, 40 insertions(+), 39 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 90f3cf19849fdc..4bd1c89ae4ee88 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -274,8 +274,13 @@ static bool bpf_pseudo_kfunc_call(const struct bpf_insn *insn)
 	       insn->src_reg == BPF_PSEUDO_KFUNC_CALL;
 }
 
+struct bpf_map_desc {
+	struct bpf_map *ptr;
+	int uid;
+};
+
 struct bpf_call_arg_meta {
-	struct bpf_map *map_ptr;
+	struct bpf_map_desc map;
 	bool raw_mode;
 	bool pkt_access;
 	u8 release_regno;
@@ -285,7 +290,6 @@ struct bpf_call_arg_meta {
 	u64 msize_max_value;
 	int ref_obj_id;
 	int dynptr_id;
-	int map_uid;
 	int func_id;
 	struct btf *btf;
 	u32 btf_id;
@@ -345,10 +349,7 @@ struct bpf_kfunc_call_arg_meta {
 		u8 spi;
 		u8 frameno;
 	} iter;
-	struct {
-		struct bpf_map *ptr;
-		int uid;
-	} map;
+	struct bpf_map_desc map;
 	u64 mem_size;
 };
 
@@ -8577,7 +8578,7 @@ static int process_timer_func(struct bpf_verifier_env *env, int regno,
 	if (err)
 		return err;
 
-	if (meta->map_ptr) {
+	if (meta->map.ptr) {
 		verifier_bug(env, "Two map pointers in a timer helper");
 		return -EFAULT;
 	}
@@ -8585,8 +8586,8 @@ static int process_timer_func(struct bpf_verifier_env *env, int regno,
 		verbose(env, "bpf_timer cannot be used for PREEMPT_RT.\n");
 		return -EOPNOTSUPP;
 	}
-	meta->map_uid = reg->map_uid;
-	meta->map_ptr = map;
+	meta->map.uid = reg->map_uid;
+	meta->map.ptr = map;
 	return 0;
 }
 
@@ -8650,7 +8651,7 @@ static int process_kptr_func(struct bpf_verifier_env *env, int regno,
 			return -EINVAL;
 		}
 		rec = map_ptr->record;
-		meta->map_ptr = map_ptr;
+		meta->map.ptr = map_ptr;
 	}
 
 	if (!tnum_is_const(reg->var_off)) {
@@ -9157,13 +9158,13 @@ static int resolve_map_arg_type(struct bpf_verifier_env *env,
 				 const struct bpf_call_arg_meta *meta,
 				 enum bpf_arg_type *arg_type)
 {
-	if (!meta->map_ptr) {
+	if (!meta->map.ptr) {
 		/* kernel subsystem misconfigured verifier */
 		verifier_bug(env, "invalid map_ptr to access map->type");
 		return -EFAULT;
 	}
 
-	switch (meta->map_ptr->map_type) {
+	switch (meta->map.ptr->map_type) {
 	case BPF_MAP_TYPE_SOCKMAP:
 	case BPF_MAP_TYPE_SOCKHASH:
 		if (*arg_type == ARG_PTR_TO_MAP_VALUE) {
@@ -9812,7 +9813,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 	switch (base_type(arg_type)) {
 	case ARG_CONST_MAP_PTR:
 		/* bpf_map_xxx(map_ptr) call: remember that map_ptr */
-		if (meta->map_ptr) {
+		if (meta->map.ptr) {
 			/* Use map_uid (which is unique id of inner map) to reject:
 			 * inner_map1 = bpf_map_lookup_elem(outer_map, key1)
 			 * inner_map2 = bpf_map_lookup_elem(outer_map, key2)
@@ -9825,23 +9826,23 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 			 *
 			 * Comparing map_ptr is enough to distinguish normal and outer maps.
 			 */
-			if (meta->map_ptr != reg->map_ptr ||
-			    meta->map_uid != reg->map_uid) {
+			if (meta->map.ptr != reg->map_ptr ||
+			    meta->map.uid != reg->map_uid) {
 				verbose(env,
 					"timer pointer in R1 map_uid=%d doesn't match map pointer in R2 map_uid=%d\n",
-					meta->map_uid, reg->map_uid);
+					meta->map.uid, reg->map_uid);
 				return -EINVAL;
 			}
 		}
-		meta->map_ptr = reg->map_ptr;
-		meta->map_uid = reg->map_uid;
+		meta->map.ptr = reg->map_ptr;
+		meta->map.uid = reg->map_uid;
 		break;
 	case ARG_PTR_TO_MAP_KEY:
 		/* bpf_map_xxx(..., map_ptr, ..., key) call:
 		 * check that [key, key + map->key_size) are within
 		 * stack limits and initialized
 		 */
-		if (!meta->map_ptr) {
+		if (!meta->map.ptr) {
 			/* in function declaration map_ptr must come before
 			 * map_key, so that it's verified and known before
 			 * we have to check map_key here. Otherwise it means
@@ -9850,11 +9851,11 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 			verifier_bug(env, "invalid map_ptr to access map->key");
 			return -EFAULT;
 		}
-		key_size = meta->map_ptr->key_size;
+		key_size = meta->map.ptr->key_size;
 		err = check_helper_mem_access(env, regno, key_size, BPF_READ, false, NULL);
 		if (err)
 			return err;
-		if (can_elide_value_nullness(meta->map_ptr->map_type)) {
+		if (can_elide_value_nullness(meta->map.ptr->map_type)) {
 			err = get_constant_map_key(env, reg, key_size, &meta->const_map_key);
 			if (err < 0) {
 				meta->const_map_key = -1;
@@ -9872,13 +9873,13 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 		/* bpf_map_xxx(..., map_ptr, ..., value) call:
 		 * check [value, value + map->value_size) validity
 		 */
-		if (!meta->map_ptr) {
+		if (!meta->map.ptr) {
 			/* kernel subsystem misconfigured verifier */
 			verifier_bug(env, "invalid map_ptr to access map->value");
 			return -EFAULT;
 		}
 		meta->raw_mode = arg_type & MEM_UNINIT;
-		err = check_helper_mem_access(env, regno, meta->map_ptr->value_size,
+		err = check_helper_mem_access(env, regno, meta->map.ptr->value_size,
 					      arg_type & MEM_WRITE ? BPF_WRITE : BPF_READ,
 					      false, meta);
 		break;
@@ -11196,7 +11197,7 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
 		int func_id, int insn_idx)
 {
 	struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
-	struct bpf_map *map = meta->map_ptr;
+	struct bpf_map *map = meta->map.ptr;
 
 	if (func_id != BPF_FUNC_tail_call &&
 	    func_id != BPF_FUNC_map_lookup_elem &&
@@ -11229,11 +11230,11 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
 	}
 
 	if (!aux->map_ptr_state.map_ptr)
-		bpf_map_ptr_store(aux, meta->map_ptr,
-				  !meta->map_ptr->bypass_spec_v1, false);
-	else if (aux->map_ptr_state.map_ptr != meta->map_ptr)
-		bpf_map_ptr_store(aux, meta->map_ptr,
-				  !meta->map_ptr->bypass_spec_v1, true);
+		bpf_map_ptr_store(aux, meta->map.ptr,
+				  !meta->map.ptr->bypass_spec_v1, false);
+	else if (aux->map_ptr_state.map_ptr != meta->map.ptr)
+		bpf_map_ptr_store(aux, meta->map.ptr,
+				  !meta->map.ptr->bypass_spec_v1, true);
 	return 0;
 }
 
@@ -11243,7 +11244,7 @@ record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
 {
 	struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
 	struct bpf_reg_state *reg;
-	struct bpf_map *map = meta->map_ptr;
+	struct bpf_map *map = meta->map.ptr;
 	u64 val, max;
 	int err;
 
@@ -11809,22 +11810,22 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 		 * can check 'value_size' boundary of memory access
 		 * to map element returned from bpf_map_lookup_elem()
 		 */
-		if (meta.map_ptr == NULL) {
+		if (meta.map.ptr == NULL) {
 			verifier_bug(env, "unexpected null map_ptr");
 			return -EFAULT;
 		}
 
 		if (func_id == BPF_FUNC_map_lookup_elem &&
-		    can_elide_value_nullness(meta.map_ptr->map_type) &&
+		    can_elide_value_nullness(meta.map.ptr->map_type) &&
 		    meta.const_map_key >= 0 &&
-		    meta.const_map_key < meta.map_ptr->max_entries)
+		    meta.const_map_key < meta.map.ptr->max_entries)
 			ret_flag &= ~PTR_MAYBE_NULL;
 
-		regs[BPF_REG_0].map_ptr = meta.map_ptr;
-		regs[BPF_REG_0].map_uid = meta.map_uid;
+		regs[BPF_REG_0].map_ptr = meta.map.ptr;
+		regs[BPF_REG_0].map_uid = meta.map.uid;
 		regs[BPF_REG_0].type = PTR_TO_MAP_VALUE | ret_flag;
 		if (!type_may_be_null(ret_flag) &&
-		    btf_record_has_field(meta.map_ptr->record, BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK)) {
+		    btf_record_has_field(meta.map.ptr->record, BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK)) {
 			regs[BPF_REG_0].id = ++env->id_gen;
 		}
 		break;
@@ -11927,7 +11928,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 	if (type_may_be_null(regs[BPF_REG_0].type))
 		regs[BPF_REG_0].id = ++env->id_gen;
 
-	if (helper_multiple_ref_obj_use(func_id, meta.map_ptr)) {
+	if (helper_multiple_ref_obj_use(func_id, meta.map.ptr)) {
 		verifier_bug(env, "func %s#%d sets ref_obj_id more than once",
 			     func_id_name(func_id), func_id);
 		return -EFAULT;
@@ -11939,7 +11940,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 	if (is_ptr_cast_function(func_id) || is_dynptr_ref_function(func_id)) {
 		/* For release_reference() */
 		regs[BPF_REG_0].ref_obj_id = meta.ref_obj_id;
-	} else if (is_acquire_function(func_id, meta.map_ptr)) {
+	} else if (is_acquire_function(func_id, meta.map.ptr)) {
 		int id = acquire_reference(env, insn_idx);
 
 		if (id < 0)
@@ -11954,7 +11955,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 	if (err)
 		return err;
 
-	err = check_map_func_compatibility(env, meta.map_ptr, func_id);
+	err = check_map_func_compatibility(env, meta.map.ptr, func_id);
 	if (err)
 		return err;
 
-- 
2.53.0

[PATCH 6.18.y 3/3] bpf: Keep dynamic inner array lookups nullable

[Sasha Levin]

From: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>

[ Upstream commit 53040a81ae57cdca8af8ac36fe4e661730cf7c6b ]

An ARRAY_OF_MAPS can use an array created with BPF_F_INNER_MAP as its
inner map template. A concrete inner array with a different max_entries
value can then replace the template.

After a successful outer map lookup, the verifier represents the
resulting map pointer using the inner map template. Const-key lookup
nullness elision consequently uses the template max_entries even though
the runtime helper uses the concrete inner map max_entries.

Do not elide lookup result nullness for maps marked with BPF_F_INNER_MAP,
because the template max_entries does not prove that the key is in bounds
for the concrete runtime map.

Fixes: d2102f2f5d75 ("bpf: verifier: Support eliding map lookup nullness")
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20260607-f01-v2-v2-1-da48453146e8@mails.tsinghua.edu.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/bpf/verifier.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 4bd1c89ae4ee88..cb1893eb5ee11b 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -9705,7 +9705,7 @@ static int get_constant_map_key(struct bpf_verifier_env *env,
 	return 0;
 }
 
-static bool can_elide_value_nullness(enum bpf_map_type type);
+static bool can_elide_value_nullness(const struct bpf_map *map);
 
 static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 			  struct bpf_call_arg_meta *meta,
@@ -9855,7 +9855,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 		err = check_helper_mem_access(env, regno, key_size, BPF_READ, false, NULL);
 		if (err)
 			return err;
-		if (can_elide_value_nullness(meta->map.ptr->map_type)) {
+		if (can_elide_value_nullness(meta->map.ptr)) {
 			err = get_constant_map_key(env, reg, key_size, &meta->const_map_key);
 			if (err < 0) {
 				meta->const_map_key = -1;
@@ -11428,13 +11428,16 @@ static void update_loop_inline_state(struct bpf_verifier_env *env, u32 subprogno
 				 state->callback_subprogno == subprogno);
 }
 
-/* Returns whether or not the given map type can potentially elide
+/* Returns whether or not the given map can potentially elide
  * lookup return value nullness check. This is possible if the key
  * is statically known.
  */
-static bool can_elide_value_nullness(enum bpf_map_type type)
+static bool can_elide_value_nullness(const struct bpf_map *map)
 {
-	switch (type) {
+	if (map->map_flags & BPF_F_INNER_MAP)
+		return false;
+
+	switch (map->map_type) {
 	case BPF_MAP_TYPE_ARRAY:
 	case BPF_MAP_TYPE_PERCPU_ARRAY:
 		return true;
@@ -11816,7 +11819,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 		}
 
 		if (func_id == BPF_FUNC_map_lookup_elem &&
-		    can_elide_value_nullness(meta.map.ptr->map_type) &&
+		    can_elide_value_nullness(meta.map.ptr) &&
 		    meta.const_map_key >= 0 &&
 		    meta.const_map_key < meta.map.ptr->max_entries)
 			ret_flag &= ~PTR_MAYBE_NULL;
-- 
2.53.0