[merged mm-stable] block-zram-do-not-keep-dangling-zcomp-pointer-after-zram-reset.patch removed from -mm tree

[merged mm-stable] block-zram-do-not-keep-dangling-zcomp-pointer-after-zram-reset.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: drivers/block/zram/zram_drv.c: do not keep dangling zcomp pointer after zram reset
has been removed from the -mm tree.  Its filename was
     block-zram-do-not-keep-dangling-zcomp-pointer-after-zram-reset.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: drivers/block/zram/zram_drv.c: do not keep dangling zcomp pointer after zram reset
Date: Wed, 24 Aug 2022 12:51:00 +0900

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>
---

 drivers/block/zram/zram_drv.c |   13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

--- a/drivers/block/zram/zram_drv.c~block-zram-do-not-keep-dangling-zcomp-pointer-after-zram-reset
+++ a/drivers/block/zram/zram_drv.c
@@ -1710,9 +1710,6 @@ out:
 
 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 zra
 		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);
_

Patches currently in -mm which might be from senozhatsky@chromium.org are