The patch titled
Subject: zram: fix uninitialized ZRAM not releasing backing device
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
zram-fix-uninitialized-zram-not-releasing-backing-device.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-fix-uninitialized-zram-not-releasing-backing-device.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kairui Song <kasong@xxxxxxxxxxx>
Subject: zram: fix uninitialized ZRAM not releasing backing device
Date: Thu, 5 Dec 2024 02:02:24 +0800
Setting backing device is done before ZRAM initialization. If we set the
backing device, then remove the ZRAM module without initializing the
device, the backing device reference will be leaked and the device will be
hold forever.
Fix this by always check and release the backing device when resetting or
removing ZRAM.
Link: https://lkml.kernel.org/r/20241204180224.31069-3-ryncsn@xxxxxxxxx
Fixes: 013bf95a83ec ("zram: add interface to specif backing device")
Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
Reported-by: Desheng Wu <deshengwu@xxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/block/zram/zram_drv.c~zram-fix-uninitialized-zram-not-releasing-backing-device
+++ a/drivers/block/zram/zram_drv.c
@@ -2335,6 +2335,9 @@ static void zram_reset_device(struct zra
zram->limit_pages = 0;
if (!init_done(zram)) {
+ /* Backing device could be set before ZRAM initialization. */
+ reset_bdev(zram);
+
up_write(&zram->init_lock);
return;
}
_
Patches currently in -mm which might be from kasong@xxxxxxxxxxx are
zram-refuse-to-use-zero-sized-block-device-as-backing-device.patch
zram-fix-uninitialized-zram-not-releasing-backing-device.patch
