diff options
| author | Jiang Liu <liuj97@gmail.com> | 2013-06-07 00:07:22 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-11 18:35:23 -0700 |
| commit | b74c38d5b6af46482480f6f8b83633e2971a0ed8 (patch) | |
| tree | 23baeb18e5dba18a99404509006583bcc7947e5c | |
| parent | 14d33c9b86b368fd6cab62e61074fa115018f1f8 (diff) | |
zram: avoid invalid memory access in zram_exit()
commit 6030ea9b35971a4200062f010341ab832e878ac9 upstream.
Memory for zram->disk object may have already been freed after returning
from destroy_device(zram), then it's unsafe for zram_reset_device(zram)
to access zram->disk again.
We can't solve this bug by flipping the order of destroy_device(zram)
and zram_reset_device(zram), that will cause deadlock issues to the
zram sysfs handler.
So fix it by holding an extra reference to zram->disk before calling
destroy_device(zram).
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/zram/zram_drv.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index e34e3fe0ae2..ee6b67d7734 100644 --- a/drivers/staging/zram/zram_drv.c +++ b/drivers/staging/zram/zram_drv.c @@ -727,8 +727,10 @@ static void __exit zram_exit(void) for (i = 0; i < num_devices; i++) { zram = &zram_devices[i]; + get_disk(zram->disk); destroy_device(zram); zram_reset_device(zram); + put_disk(zram->disk); } unregister_blkdev(zram_major, "zram"); |