zram: fix potential UAF of zram table

JIRA: https://issues.redhat.com/browse/RHEL-77219
CVE: CVE-2025-21671

commit 212fe1c
Author: Kairui Song <kasong@tencent.com>
Date:   Tue Jan 7 14:54:46 2025 +0800

    zram: fix potential UAF of zram table

    If zram_meta_alloc failed early, it frees allocated zram->table without
    setting it NULL.  Which will potentially cause zram_meta_free to access
    the table if user reset an failed and uninitialized device.

    Link: https://lkml.kernel.org/r/20250107065446.86928-1-ryncsn@gmail.com
    Fixes: 74363ec ("zram: fix uninitialized ZRAM not releasing backing device")
    Signed-off-by: Kairui Song <kasong@tencent.com>
    Reviewed-by:  Sergey Senozhatsky <senozhatsky@chromium.org>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Ming Lei <ming.lei@redhat.com>

Author: Ming Lei

drivers/block/zram/zram_drv.c

@@ -1323,6 +1323,7 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize)
 	zram->mem_pool = zs_create_pool(zram->disk->disk_name);
 	if (!zram->mem_pool) {
 		vfree(zram->table);
+		zram->table = NULL;
 		return false;
 	}