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authorMatthew Wilcox (Oracle) <willy@infradead.org>2024-03-06 22:27:30 +0100
committerAndrew Morton <akpm@linux-foundation.org>2024-03-12 21:07:16 +0100
commitb555895c313511830762dbb2f469587a822c1759 (patch)
tree104fd75d22e55b776c5f6e3fc2dbcade37863461 /mm/swap.c
parentmm: remove folio from deferred split list before uncharging it (diff)
downloadlinux-b555895c313511830762dbb2f469587a822c1759.tar.xz
linux-b555895c313511830762dbb2f469587a822c1759.zip
mm: fix list corruption in put_pages_list
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@SJ1PR11MB6129.namprd11.prod.outlook.com/ Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/swap.c')
-rw-r--r--mm/swap.c4
1 files 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)) {