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-rw-r--r--kernel/bpf/states.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/kernel/bpf/states.c b/kernel/bpf/states.c
index 32f346ce3ffc..ea2153cf28d0 100644
--- a/kernel/bpf/states.c
+++ b/kernel/bpf/states.c
@@ -436,12 +436,10 @@ static void __clean_func_state(struct bpf_verifier_env *env,
continue;
/*
- * Only destroy spilled_ptr when hi half is dead.
- * If hi half is still live with STACK_SPILL, the
- * spilled_ptr metadata is needed for correct state
- * comparison in stacksafe().
- * is_spilled_reg() is using slot_type[7], but
- * is_spilled_scalar_after() check either slot_type[0] or [4]
+ * Only scalar spills can be degraded to raw stack bytes
+ * when their high half is dead. Pointer spills need the
+ * saved spilled_ptr metadata so partial fills keep
+ * rejecting as non-scalar register fills.
*/
if (!hi_live) {
struct bpf_reg_state *spill = &st->stack[i].spilled_ptr;
@@ -449,6 +447,9 @@ static void __clean_func_state(struct bpf_verifier_env *env,
if (lo_live && stype == STACK_SPILL) {
u8 val = STACK_MISC;
+ if (spill->type != SCALAR_VALUE)
+ continue;
+
/*
* 8 byte spill of scalar 0 where half slot is dead
* should become STACK_ZERO in lo 4 bytes.