The patch titled
mm: fix pageref leak in do_swap_page()
has been added to the -mm tree. Its filename is
mm-fix-pageref-leak-in-do_swap_page.patch
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------------------------------------------------------
Subject: mm: fix pageref leak in do_swap_page()
From: Johannes Weiner <hannes@xxxxxxxxxxx>
By the time the memory cgroup code is notified about a swapin we
already hold a reference on the fault page.
If the cgroup callback fails make sure to unlock AND release the page
reference which was taken by lookup_swap_cach(), or we leak the reference.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN mm/memory.c~mm-fix-pageref-leak-in-do_swap_page mm/memory.c
--- a/mm/memory.c~mm-fix-pageref-leak-in-do_swap_page
+++ a/mm/memory.c
@@ -2458,8 +2458,7 @@ static int do_swap_page(struct mm_struct
if (mem_cgroup_try_charge_swapin(mm, page, GFP_KERNEL, &ptr)) {
ret = VM_FAULT_OOM;
- unlock_page(page);
- goto out;
+ goto out_page;
}
/*
@@ -2521,6 +2520,7 @@ out:
out_nomap:
mem_cgroup_cancel_charge_swapin(ptr);
pte_unmap_unlock(page_table, ptl);
+out_page:
unlock_page(page);
page_cache_release(page);
return ret;
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
vmscanmemcg-reintroduce-sc-may_swap.patch
mm-fix-pageref-leak-in-do_swap_page.patch
linux-next.patch
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