Commit 6d2453c3 authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Andrew Morton
Browse files

drivers/block/zram/zram_drv.c: do not keep dangling zcomp pointer after zram reset 

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: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 67e139b0

drivers/block/zram/zram_drv.c

+4 −9
Original line number Diff line number Diff line
@@ -1710,9 +1710,6 @@ 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;
@@ -1722,17 +1719,15 @@ 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);



	/* 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);



	up_write(&zram->init_lock);