From: "Matthew Wilcox (Oracle)" willy@infradead.org
mainline inclusion from mainline-v6.9-rc1 commit b555895c313511830762dbb2f469587a822c1759 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9R3AY CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
--------------------------------
My recent change to put_pages_list() dereferences folio->lru.next after returning the folio to the page allocator. Usually this is now on the pcp list with other free folios, so we try to free an already-free folio. This only happens with lists that have more than 15 entries, so it wasn't immediately discovered. Revert to using list_for_each_safe() so we dereference lru.next before disposing of the folio.
Link: https://lkml.kernel.org/r/20240306212749.1823380-1-willy@infradead.org Fixes: 24835f899c01 ("mm: use free_unref_folios() in put_pages_list()") Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Reported-by: "Borah, Chaitanya Kumar" chaitanya.kumar.borah@intel.com Closes: https://lore.kernel.org/intel-gfx/SJ1PR11MB61292145F3B79DA58ADDDA63B9232@SJ1... Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Liu Shixin liushixin2@huawei.com --- mm/swap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/swap.c b/mm/swap.c index e43a5911b170..500a09a48dfd 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -152,10 +152,10 @@ EXPORT_SYMBOL(__folio_put); void put_pages_list(struct list_head *pages) { struct folio_batch fbatch; - struct folio *folio; + struct folio *folio, *next;
folio_batch_init(&fbatch); - list_for_each_entry(folio, pages, lru) { + list_for_each_entry_safe(folio, next, pages, lru) { if (!folio_put_testzero(folio)) continue; if (folio_test_large(folio)) {