On 17/05/2023 03:21, Peter Collingbourne wrote:
Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved the call to swap_free() before the call to set_pte_at(), which meant that the MTE tags could end up being freed before set_pte_at() had a chance to restore them. Fix it by adding a call to the arch_swap_restore() hook before the call to swap_free().
Signed-off-by: Peter Collingbourne pcc@google.com Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510... Cc: stable@vger.kernel.org # 6.1 Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") Reported-by: Qun-wei Lin (林群崴) Qun-wei.Lin@mediatek.com Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@m...
Reviewed-by: Steven Price steven.price@arm.com
v2:
- Call arch_swap_restore() directly instead of via arch_do_swap_page()
mm/memory.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/mm/memory.c b/mm/memory.c index f69fbc251198..fc25764016b3 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3932,6 +3932,13 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) } }
- /*
* Some architectures may have to restore extra metadata to the page* when reading from swap. This metadata may be indexed by swap entry* so this must be called before swap_free().*/- arch_swap_restore(entry, folio);
- /*
- Remove the swap entry and conditionally try to free up the swapcache.
- We're already holding a reference on the page but haven't mapped it