diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 39a851e690ec..76b8b7627a10 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -1243,6 +1243,11 @@ static inline void bpf_bt_set_frame_slot(struct backtrack_state *bt, u32 frame,
 	bt->stack_masks[frame] |= 1ull << slot;
 }
 
+static inline void bpf_bt_set_frame_slot_mask(struct backtrack_state *bt, u32 frame, u64 mask)
+{
+	bt->stack_masks[frame] |= mask;
+}
+
 static inline void bt_set_frame_stack_arg_slot(struct backtrack_state *bt, u32 frame, u32 slot)
 {
 	bt->stack_arg_masks[frame] |= 1 << slot;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 21a365d436a5..25aea4271cd0 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3702,14 +3702,21 @@ static int check_stack_write_var_off(struct bpf_verifier_env *env,
  * SCALAR. This function does not deal with register filling; the caller must
  * ensure that all spilled registers in the stack range have been marked as
  * read.
+ *
+ * STACK_SPILL bytes backed by spilled scalar const zeroes are also considered
+ * zero bytes. In that case, mark the contributing stack slots precise so
+ * pruning cannot reuse a zero-spill state for a later non-zero spill state.
+ *
+ * Returns an error if precision backtracking fails.
  */
-static void mark_reg_stack_read(struct bpf_verifier_env *env,
-				/* func where src register points to */
-				struct bpf_func_state *ptr_state,
-				int min_off, int max_off, int dst_regno)
+static int mark_reg_stack_read(struct bpf_verifier_env *env,
+			       /* func where src register points to */
+			       struct bpf_func_state *ptr_state,
+			       int min_off, int max_off, int dst_regno)
 {
 	struct bpf_verifier_state *vstate = env->cur_state;
 	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	u64 zero_spill_mask = 0;
 	int i, slot, spi;
 	u8 *stype;
 	int zeros = 0;
@@ -3719,19 +3726,33 @@ static void mark_reg_stack_read(struct bpf_verifier_env *env,
 		spi = slot / BPF_REG_SIZE;
 		mark_stack_slot_scratched(env, spi);
 		stype = ptr_state->stack[spi].slot_type;
-		if (stype[slot % BPF_REG_SIZE] != STACK_ZERO)
-			break;
-		zeros++;
+		if (stype[slot % BPF_REG_SIZE] == STACK_ZERO) {
+			zeros++;
+			continue;
+		}
+		if (stype[slot % BPF_REG_SIZE] == STACK_SPILL &&
+		    bpf_register_is_null(&ptr_state->stack[spi].spilled_ptr)) {
+			zero_spill_mask |= 1ull << spi;
+			zeros++;
+			continue;
+		}
+		break;
 	}
 	if (zeros == max_off - min_off) {
 		/* Any access_size read into register is zero extended,
 		 * so the whole register == const_zero.
 		 */
 		__mark_reg_const_zero(env, &state->regs[dst_regno]);
+		if (zero_spill_mask) {
+			bpf_bt_set_frame_slot_mask(&env->bt, ptr_state->frameno, zero_spill_mask);
+			return mark_chain_precision_batch(env, env->cur_state);
+		}
 	} else {
 		/* have read misc data from the stack */
 		mark_reg_unknown(env, state->regs, dst_regno);
 	}
+
+	return 0;
 }
 
 /* Read the stack at 'off' and put the results into the register indicated by
@@ -3753,6 +3774,7 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 	int i, slot = -off - 1, spi = slot / BPF_REG_SIZE;
 	struct bpf_reg_state *reg;
 	u8 *stype, type;
+	int err;
 	int insn_flags = INSN_F_STACK_ACCESS;
 	int hist_spi = spi, hist_frame = reg_state->frameno;
 
@@ -3835,7 +3857,10 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 					__mark_reg_const_zero(env, &state->regs[dst_regno]);
 					insn_flags = 0; /* not restoring original register state */
 				} else {
-					mark_reg_unknown(env, state->regs, dst_regno);
+					err = mark_reg_stack_read(env, reg_state, off, off + size,
+								  dst_regno);
+					if (err)
+						return err;
 					insn_flags = 0; /* not restoring original register state */
 				}
 			}
@@ -3880,8 +3905,11 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 			}
 			return -EACCES;
 		}
-		if (dst_regno >= 0)
-			mark_reg_stack_read(env, reg_state, off, off + size, dst_regno);
+		if (dst_regno >= 0) {
+			err = mark_reg_stack_read(env, reg_state, off, off + size, dst_regno);
+			if (err)
+				return err;
+		}
 		insn_flags = 0; /* we are not restoring spilled register */
 	}
 	if (insn_flags)
@@ -3935,7 +3963,10 @@ static int check_stack_read_var_off(struct bpf_verifier_env *env, struct bpf_reg
 
 	min_off = reg_smin(reg) + off;
 	max_off = reg_smax(reg) + off;
-	mark_reg_stack_read(env, ptr_state, min_off, max_off + size, dst_regno);
+	err = mark_reg_stack_read(env, ptr_state, min_off, max_off + size,
+				  dst_regno);
+	if (err)
+		return err;
 	check_fastcall_stack_contract(env, ptr_state, env->insn_idx, min_off);
 	return 0;
 }
diff --git a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
index 0174887e28f5..72c691333703 100644
--- a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
+++ b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
@@ -634,6 +634,32 @@ __naked void partial_stack_load_preserves_partial_zeros(void)
 	: __clobber_common);
 }
 
+SEC("raw_tp")
+__log_level(2)
+__success
+__msg("mark_precise: frame0: regs= stack=-8")
+__msg("R2=0")
+__naked void stack_load_preserves_mixed_zero_and_zero_spill(void)
+{
+	asm volatile (
+		/* fp-8 has scalar const-zero spill bytes and STACK_ZERO bytes. */
+		".8byte %[fp4_st_zero];" /* LLVM-18+: *(u32 *)(r10 -4) = 0; */
+		"r0 = 0;"
+		"*(u32 *)(r10 -8) = r0;"
+
+		"r1 = %[single_byte_buf];"
+		"r2 = *(u64 *)(r10 -8);"
+		"r1 += r2;"
+		"*(u8 *)(r1 + 0) = r2;" /* this should be fine */
+
+		"r0 = 0;"
+		"exit;"
+	:
+	: __imm_ptr(single_byte_buf),
+	  __imm_insn(fp4_st_zero, BPF_ST_MEM(BPF_W, BPF_REG_FP, -4, 0))
+	: __clobber_common);
+}
+
 char two_byte_buf[2] SEC(".data.two_byte_buf");
 
 SEC("raw_tp")
diff --git a/tools/testing/selftests/bpf/progs/verifier_var_off.c b/tools/testing/selftests/bpf/progs/verifier_var_off.c
index f345466bca68..24cd0a763673 100644
--- a/tools/testing/selftests/bpf/progs/verifier_var_off.c
+++ b/tools/testing/selftests/bpf/progs/verifier_var_off.c
@@ -59,6 +59,116 @@ __naked void stack_read_priv_vs_unpriv(void)
 "	::: __clobber_all);
 }
 
+SEC("cgroup/skb")
+__description("variable-offset stack read preserves spilled zero")
+__success
+__log_level(2)
+__msg("mark_precise: frame0: regs= stack=-8")
+__msg("R3=0")
+__retval(0)
+__naked void stack_read_var_off_preserves_spilled_zero(void)
+{
+	asm volatile ("					\
+	r0 = 0;						\
+	*(u64*)(r10 - 8) = r0;			\
+	r2 = *(u32*)(r1 + 0);				\
+	r2 &= 7;					\
+	r2 -= 8;					\
+	r2 += r10;					\
+	r3 = *(u8*)(r2 + 0);				\
+	r1 = r10;					\
+	r1 += -1;					\
+	r1 += r3;					\
+	*(u8*)(r1 + 0) = r3;			\
+	r0 = 0;						\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("cgroup/skb")
+__description("variable-offset stack read preserves spilled zero across slots")
+__success
+__log_level(2)
+__msg("mark_precise: frame0: regs= stack=-8,-16")
+__msg("R3=0")
+__retval(0)
+__naked void stack_read_var_off_preserves_spilled_zero_across_slots(void)
+{
+	asm volatile ("					\
+	r0 = 0;						\
+	*(u64*)(r10 - 8) = r0;			\
+	*(u64*)(r10 - 16) = r0;			\
+	r2 = *(u32*)(r1 + 0);				\
+	r2 &= 15;					\
+	r2 -= 16;					\
+	r2 += r10;					\
+	r3 = *(u8*)(r2 + 0);				\
+	r1 = r10;					\
+	r1 += -1;					\
+	r1 += r3;					\
+	*(u8*)(r1 + 0) = r3;			\
+	r0 = 0;						\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("cgroup/skb")
+__description("variable-offset stack read preserves partial spilled zero")
+__success
+__log_level(2)
+__msg("mark_precise: frame0: regs= stack=-8")
+__msg("R3=0")
+__retval(0)
+__naked void stack_read_var_off_preserves_partial_spilled_zero(void)
+{
+	asm volatile ("					\
+	r0 = 0;						\
+	*(u8*)(r10 - 9) = r0;			\
+	*(u8*)(r10 - 10) = r0;			\
+	*(u8*)(r10 - 11) = r0;			\
+	*(u8*)(r10 - 12) = r0;			\
+	*(u8*)(r10 - 13) = r0;			\
+	*(u8*)(r10 - 14) = r0;			\
+	*(u8*)(r10 - 15) = r0;			\
+	*(u32*)(r10 - 8) = r0;			\
+	r2 = *(u32*)(r1 + 0);				\
+	r2 &= 15;					\
+	if r2 > 10 goto l0_%=;			\
+	r2 -= 15;					\
+	r2 += r10;					\
+	r3 = *(u8*)(r2 + 0);				\
+	r1 = r10;					\
+	r1 += -1;					\
+	r1 += r3;					\
+	*(u8*)(r1 + 0) = r3;			\
+l0_%=: r0 = 0;					\
+	exit;						\
+"	::: __clobber_all);
+}
+
+SEC("cgroup/skb")
+__description("variable-offset stack read partial spill with misc data")
+__failure
+__msg("invalid variable-offset write to stack R1")
+__naked void stack_read_var_off_partial_spill_with_misc_data(void)
+{
+	asm volatile ("					\
+	r0 = 0;						\
+	*(u32*)(r10 - 8) = r0;			\
+	r2 = *(u32*)(r1 + 0);				\
+	r2 &= 7;					\
+	r2 -= 8;					\
+	r2 += r10;					\
+	r3 = *(u8*)(r2 + 0);				\
+	r1 = r10;					\
+	r1 += -1;					\
+	r1 += r3;					\
+	*(u8*)(r1 + 0) = 0;			\
+	r0 = 0;						\
+	exit;						\
+"	::: __clobber_all);
+}
+
 SEC("cgroup/skb")
 __description("variable-offset stack read, uninitialized")
 __success