4.19-stable patches

added patches:
	mm-hugetlb-take-hugetlb_lock-before-decrementing-h-resv_huge_pages.patch

diff --git a/queue-4.19/mm-hugetlb-take-hugetlb_lock-before-decrementing-h-resv_huge_pages.patch b/queue-4.19/mm-hugetlb-take-hugetlb_lock-before-decrementing-h-resv_huge_pages.patch
new file mode 100644 (file)
index 0000000..0cfdc11
--- /dev/null
+++ b/queue-4.19/mm-hugetlb-take-hugetlb_lock-before-decrementing-h-resv_huge_pages.patch
@@ -0,0 +1,50 @@
+From 12df140f0bdfae5dcfc81800970dd7f6f632e00c Mon Sep 17 00:00:00 2001
+From: Rik van Riel <riel@surriel.com>
+Date: Mon, 17 Oct 2022 20:25:05 -0400
+Subject: mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages
+
+From: Rik van Riel <riel@surriel.com>
+
+commit 12df140f0bdfae5dcfc81800970dd7f6f632e00c upstream.
+
+The h->*_huge_pages counters are protected by the hugetlb_lock, but
+alloc_huge_page has a corner case where it can decrement the counter
+outside of the lock.
+
+This could lead to a corrupted value of h->resv_huge_pages, which we have
+observed on our systems.
+
+Take the hugetlb_lock before decrementing h->resv_huge_pages to avoid a
+potential race.
+
+Link: https://lkml.kernel.org/r/20221017202505.0e6a4fcd@imladris.surriel.com
+Fixes: a88c76954804 ("mm: hugetlb: fix hugepage memory leak caused by wrong reserve count")
+Signed-off-by: Rik van Riel <riel@surriel.com>
+Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
+Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
+Cc: Glen McCready <gkmccready@meta.com>
+Cc: Mike Kravetz <mike.kravetz@oracle.com>
+Cc: Muchun Song <songmuchun@bytedance.com>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/hugetlb.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/mm/hugetlb.c
++++ b/mm/hugetlb.c
+@@ -2116,11 +2116,11 @@ struct page *alloc_huge_page(struct vm_a
+               page = alloc_buddy_huge_page_with_mpol(h, vma, addr);
+               if (!page)
+                       goto out_uncharge_cgroup;
++              spin_lock(&hugetlb_lock);
+               if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) {
+                       SetPagePrivate(page);
+                       h->resv_huge_pages--;
+               }
+-              spin_lock(&hugetlb_lock);
+               list_move(&page->lru, &h->hugepage_activelist);
+               /* Fall through */
+       }

diff --git a/queue-4.19/series b/queue-4.19/series
index 51f988fdb5907ec801bfbb430c9a214fdd1d214c..f0dda54a3b2cd994769f6526db2e2447ce6c0266 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -44,3 +44,4 @@ perf-auxtrace-fix-address-filter-symbol-name-match-for-modules.patch
 s390-futex-add-missing-ex_table-entry-to-__futex_atomic_op.patch
 xen-gntdev-don-t-ignore-kernel-unmapping-error.patch
 xen-gntdev-prevent-leaking-grants.patch
+mm-hugetlb-take-hugetlb_lock-before-decrementing-h-resv_huge_pages.patch