5.10-stable review patch. If anyone has any objections, please let me know.
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From: Sergey Senozhatsky senozhatsky@chromium.org
[ Upstream commit 6d2453c3dbc5f70eafc1c866289a90a1fc57ce18 ]
We do all reset operations under write lock, so we don't need to save ->disksize and ->comp to stack variables. Another thing is that ->comp is freed during zram reset, but comp pointer is not NULL-ed, so zram keeps the freed pointer value.
Link: https://lkml.kernel.org/r/20220824035100.971816-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky senozhatsky@chromium.org Cc: Minchan Kim minchan@kernel.org Cc: Nitin Gupta ngupta@vflare.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Stable-dep-of: 74363ec674cb ("zram: fix uninitialized ZRAM not releasing backing device") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/block/zram/zram_drv.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 8f38e5a1a63f..8e13586be8c9 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1690,9 +1690,6 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
static void zram_reset_device(struct zram *zram) { - struct zcomp *comp; - u64 disksize; - down_write(&zram->init_lock);
zram->limit_pages = 0; @@ -1702,18 +1699,16 @@ static void zram_reset_device(struct zram *zram) return; }
- comp = zram->comp; - disksize = zram->disksize; - zram->disksize = 0; - set_capacity_and_notify(zram->disk, 0); part_stat_set_all(&zram->disk->part0, 0);
up_write(&zram->init_lock); /* I/O operation under all of CPU are done so let's free */ - zram_meta_free(zram, disksize); + zram_meta_free(zram, zram->disksize); + zram->disksize = 0; memset(&zram->stats, 0, sizeof(zram->stats)); - zcomp_destroy(comp); + zcomp_destroy(zram->comp); + zram->comp = NULL; reset_bdev(zram); }