md: bcache: check the return value of kzalloc() in detached_dev_do_request()

mainline inclusion
from v5.19-rc1
commit 40f567bb
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I59A5L?from=project-issue
CVE: N/A

------------------------------------------

The function kzalloc() in detached_dev_do_request() can fail, so its
return value should be checked.

Fixes: bc082a55 ("bcache: fix inaccurate io state for detached bcache devices")
Reported-by: NTOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: NJia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: NColy Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220527152818.27545-4-colyli@suse.deSigned-off-by: NJens Axboe <axboe@kernel.dk>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/md/bcache/request.c

@@ -1104,6 +1104,12 @@ static void detached_dev_do_request(struct bcache_device *d, struct bio *bio)
 	 * which would call closure_get(&dc->disk.cl)
 	 */
 	ddip = kzalloc(sizeof(struct detached_dev_io_private), GFP_NOIO);
+	if (!ddip) {
+		bio->bi_status = BLK_STS_RESOURCE;
+		bio->bi_end_io(bio);
+		return;
+	}
+
 	ddip->d = d;
 	/* Count on the bcache device */
 	ddip->start_time = part_start_io_acct(d->disk, &ddip->part, bio);