* [PATCH] md: bcache: check the return value of kzalloc() in detached_dev_do_request()
@ 2022-02-25 8:20 Jia-Ju Bai
2022-03-02 10:11 ` Coly Li
0 siblings, 1 reply; 3+ messages in thread
From: Jia-Ju Bai @ 2022-02-25 8:20 UTC (permalink / raw)
To: colyli, kent.overstreet; +Cc: linux-bcache, linux-kernel, Jia-Ju Bai
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@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
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);
+ if (!ddip)
+ return;
ddip->d = d;
/* Count on the bcache device */
ddip->orig_bdev = orig_bdev;
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] md: bcache: check the return value of kzalloc() in detached_dev_do_request()
2022-02-25 8:20 [PATCH] md: bcache: check the return value of kzalloc() in detached_dev_do_request() Jia-Ju Bai
@ 2022-03-02 10:11 ` Coly Li
2022-03-03 1:44 ` Jia-Ju Bai
0 siblings, 1 reply; 3+ messages in thread
From: Coly Li @ 2022-03-02 10:11 UTC (permalink / raw)
To: Jia-Ju Bai; +Cc: linux-bcache, linux-kernel, kent.overstreet
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@tsinghua.edu.cn>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
> 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;
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] md: bcache: check the return value of kzalloc() in detached_dev_do_request()
2022-03-02 10:11 ` Coly Li
@ 2022-03-03 1:44 ` Jia-Ju Bai
0 siblings, 0 replies; 3+ messages in thread
From: Jia-Ju Bai @ 2022-03-03 1:44 UTC (permalink / raw)
To: Coly Li; +Cc: linux-bcache, linux-kernel, kent.overstreet
On 2022/3/2 18:11, Coly Li wrote:
> 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@tsinghua.edu.cn>
>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
>> ---
>> 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;
>
Hi Coly,
Thanks for the advice!
I will send a V2 patch.
Best wishes,
Jia-Ju Bai
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-02-25 8:20 [PATCH] md: bcache: check the return value of kzalloc() in detached_dev_do_request() Jia-Ju Bai
2022-03-02 10:11 ` Coly Li
2022-03-03 1:44 ` Jia-Ju Bai
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