On 2/25/22 4:20 PM, Jia-Ju Bai wrote:
The function kzalloc() in detached_dev_do_request() can fail, so its
return value should be checked.
Fixes: bc082a55d25c (bcache: fix inaccurate io state for detached bcache devices)
Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>
Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/md/bcache/request.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index d15aae6c51c1..1b5ccfa93b8c 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -1107,6 +1107,8 @@ 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);
Yes this is a potential problem, may result NULL pointer deference.
+ if (!ddip)
+ return;
The fix here is incorrect. A proper way to fix might be something like this,
if (!ddip) {
bio->bi_status = BLK_STS_RESOURCE;
bio->bi_end_io(bio);
return;
}
The orignal patch will make I/O task be in sleep forever.
ddip->d = d;
/* Count on the bcache device */
ddip->orig_bdev = orig_bdev;
