| From: Usama Arif <usamaarif642@gmail.com> |
| Subject: mm: set p->zeromap to NULL after freeing it |
| Date: Wed Jul 10 18:37:57 2024 +0100 |
| |
| alloc_swap_info can reuse swap_info_struct from previously used swap. |
| Reset p->zeromap to NULL so that its not set to a corrupted pointer from |
| previous swap. |
| |
| Signed-off-by: Usama Arif <usamaarif642@gmail.com> |
| Reported-by: kernel test robot <oliver.sang@intel.com> |
| Closes: https://lore.kernel.org/oe-lkp/202407101031.c6c3c651-lkp@intel.com |
| Cc: Hugh Dickins <hughd@google.com> |
| Cc: Andi Kleen <ak@linux.intel.com> |
| Cc: Chengming Zhou <chengming.zhou@linux.dev> |
| Cc: David Hildenbrand <david@redhat.com> |
| Cc: Huang Ying <ying.huang@intel.com> |
| Cc: Johannes Weiner <hannes@cmpxchg.org> |
| Cc: Matthew Wilcox (Oracle) <willy@infradead.org> |
| Cc: Nhat Pham <nphamcs@gmail.com> |
| Cc: Shakeel Butt <shakeel.butt@linux.dev> |
| Cc: Yosry Ahmed <yosryahmed@google.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| mm/swapfile.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/mm/swapfile.c~mm-set-p-zeromap-to-null-after-freeing-it |
| +++ a/mm/swapfile.c |
| @@ -2654,6 +2654,7 @@ SYSCALL_DEFINE1(swapoff, const char __us |
| p->cluster_next_cpu = NULL; |
| vfree(swap_map); |
| kvfree(p->zeromap); |
| + p->zeromap = NULL; |
| kvfree(cluster_info); |
| /* Destroy swap account information */ |
| swap_cgroup_swapoff(p->type); |
| @@ -3346,6 +3347,7 @@ bad_swap: |
| spin_unlock(&swap_lock); |
| vfree(swap_map); |
| kvfree(p->zeromap); |
| + p->zeromap = NULL; |
| kvfree(cluster_info); |
| if (inced_nr_rotate_swap) |
| atomic_dec(&nr_rotate_swap); |
| _ |
