Subject: + zram-fix-race-between-reset-and-flushing-pending-work.patch added to -mm tree
To: minchan@xxxxxxxxxx,jmarchan@xxxxxxxxxx,ngupta@xxxxxxxxxx,sergey.senozhatsky@xxxxxxxxx,stable@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 13 Jan 2014 15:59:57 -0800
The patch titled
Subject: zram: fix race between reset and flushing pending work
has been added to the -mm tree. Its filename is
zram-fix-race-between-reset-and-flushing-pending-work.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/zram-fix-race-between-reset-and-flushing-pending-work.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/zram-fix-race-between-reset-and-flushing-pending-work.patch
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------------------------------------------------------
From: Minchan Kim <minchan@xxxxxxxxxx>
Subject: zram: fix race between reset and flushing pending work
Dan and Sergey reported that there is a racy between reset and flushing of
pending work so that it could make oops by freeing zram->meta in reset
while zram_slot_free can access zram->meta if new request is adding during
the race window.
This patch moves flush after taking init_lock so it prevents new request
so that it closes the race.
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Nitin Gupta <ngupta@xxxxxxxxxx>
Cc: Jerome Marchand <jmarchan@xxxxxxxxxx>
Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN drivers/block/zram/zram_drv.c~zram-fix-race-between-reset-and-flushing-pending-work drivers/block/zram/zram_drv.c
--- a/drivers/block/zram/zram_drv.c~zram-fix-race-between-reset-and-flushing-pending-work
+++ a/drivers/block/zram/zram_drv.c
@@ -553,14 +553,14 @@ static void zram_reset_device(struct zra
size_t index;
struct zram_meta *meta;
- flush_work(&zram->free_work);
-
down_write(&zram->init_lock);
if (!zram->init_done) {
up_write(&zram->init_lock);
return;
}
+ flush_work(&zram->free_work);
+
meta = zram->meta;
zram->init_done = 0;
_
Patches currently in -mm which might be from minchan@xxxxxxxxxx are
mm-remove-bug_on-from-mlock_vma_page.patch
mm-hugetlb-use-get_page_foll-in-follow_hugetlb_page.patch
mm-hugetlbfs-move-the-put-get_page-slab-and-hugetlbfs-optimization-in-a-faster-path.patch
mm-thp-optimize-compound_trans_huge.patch
mm-tail-page-refcounting-optimization-for-slab-and-hugetlbfs.patch
mm-hugetlbfs-use-__compound_tail_refcounted-in-__get_page_tail-too.patch
mm-hugetlbc-simplify-pageheadhuge-and-pagehuge.patch
mm-swapc-reorganize-put_compound_page.patch
mm-hugetlbc-defer-pageheadhuge-symbol-export.patch
memblock-numa-introduce-flags-field-into-memblock.patch
memblock-mem_hotplug-introduce-memblock_hotplug-flag-to-mark-hotpluggable-regions.patch
memblock-make-memblock_set_node-support-different-memblock_type.patch
acpi-numa-mem_hotplug-mark-hotpluggable-memory-in-memblock.patch
acpi-numa-mem_hotplug-mark-all-nodes-the-kernel-resides-un-hotpluggable.patch
memblock-mem_hotplug-make-memblock-skip-hotpluggable-regions-if-needed.patch
x86-numa-acpi-memory-hotplug-make-movable_node-have-higher-priority.patch
mm-zswapc-change-params-from-hidden-to-ro.patch
mm-zswap-check-all-pool-pages-instead-of-one-pools-pages.patch
swap-add-a-simple-detector-for-inappropriate-swapin-readahead.patch
linux-next.patch
zsmalloc-move-it-under-mm.patch
zram-promote-zram-from-staging.patch
zram-remove-old-private-project-comment.patch
zram-add-copyright.patch
zsmalloc-add-copyright.patch
zram-add-zram-maintainers.patch
zsmalloc-add-maintainers.patch
zram-fix-race-between-reset-and-flushing-pending-work.patch
zram-delay-pending-free-request-in-read-path.patch
zram-remove-unnecessary-free.patch
debugging-keep-track-of-page-owners.patch
zram-use-atomic-operation-for-stat.patch
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