diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 233472a871be..a0830ad6bebb 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6394,11 +6394,23 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, struct b
 
 	if (!err && size < BPF_REG_SIZE && value_regno >= 0 && t == BPF_READ &&
 	    regs[value_regno].type == SCALAR_VALUE) {
-		if (!is_ldsx)
+		if (!is_ldsx) {
 			/* b/h/w load zero-extends, mark upper bits as known 0 */
 			coerce_reg_to_size(&regs[value_regno], size);
-		else
+		} else {
+			/*
+			 * Sign-extension can change the register value relative
+			 * to a scalar it is linked with by id (e.g. a zero-
+			 * extending fill of the same spilled stack slot), thus
+			 * drop the shared id in that case.
+			 */
+			bool no_sext = reg_umax(&regs[value_regno]) <
+					(1ULL << (size * BITS_PER_BYTE - 1));
+
 			coerce_reg_to_size_sx(&regs[value_regno], size);
+			if (!no_sext)
+				clear_scalar_id(&regs[value_regno]);
+		}
 	}
 	return err;
 }