mm: fix missing page table unmap for stack guard page failure case
.. which didn't show up in my tests because it's a no-op on x86-64 and
most other architectures. But we enter the function with the last-level
page table mapped, and should unmap it at exit.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory.c b/mm/memory.c
index 9606ceb..9b3b73f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2792,8 +2792,10 @@
spinlock_t *ptl;
pte_t entry;
- if (check_stack_guard_page(vma, address) < 0)
+ if (check_stack_guard_page(vma, address) < 0) {
+ pte_unmap(page_table);
return VM_FAULT_SIGBUS;
+ }
if (!(flags & FAULT_FLAG_WRITE)) {
entry = pte_mkspecial(pfn_pte(my_zero_pfn(address),