2018-12-23 16:28:09

by Matias Bjørling

Subject: Re: [PATCH] lightnvm: pblk: fix use-after-free bug

On 12/22/18 8:39 AM, Gustavo A. R. Silva wrote:
> Remove one of the calls to function bio_put(), so *bio* is only
> freed once.
>
> Notice that bio is being dereferenced in bio_put(), hence leading to
> a use-after-free bug once *bio* has already been freed.
>
> Addresses-Coverity-ID: 1475952 ("Use after free")
> Fixes: 55d8ec35398e ("lightnvm: pblk: support packed metadata")
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> drivers/lightnvm/pblk-recovery.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
> index 3fcf062d752c..5ee20da7bdb3 100644
> --- a/drivers/lightnvm/pblk-recovery.c
> +++ b/drivers/lightnvm/pblk-recovery.c
> @@ -418,7 +418,6 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
> if (ret) {
> pblk_err(pblk, "I/O submission failed: %d\n", ret);
> bio_put(bio);
> - bio_put(bio);
> return ret;
> }
>
>

Thanks Gustavo. I missed that one.

Jens, if possible could you please pick this up?

Happy holidays!

2018-12-23 16:30:30

by Gustavo A. R. Silva

Subject: Re: [PATCH] lightnvm: pblk: fix use-after-free bug

On 12/22/18 12:30 PM, Matias Bjørling wrote:
> On 12/22/18 8:39 AM, Gustavo A. R. Silva wrote:
>> Remove one of the calls to function bio_put(), so *bio* is only
>> freed once.
>>
>> Notice that bio is being dereferenced in bio_put(), hence leading to
>> a use-after-free bug once *bio* has already been freed.
>>
>> Addresses-Coverity-ID: 1475952 ("Use after free")
>> Fixes: 55d8ec35398e ("lightnvm: pblk: support packed metadata")
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>>   drivers/lightnvm/pblk-recovery.c | 1 -
>>   1 file changed, 1 deletion(-)
>>
>> diff --git a/drivers/lightnvm/pblk-recovery.c
>> b/drivers/lightnvm/pblk-recovery.c
>> index 3fcf062d752c..5ee20da7bdb3 100644
>> --- a/drivers/lightnvm/pblk-recovery.c
>> +++ b/drivers/lightnvm/pblk-recovery.c
>> @@ -418,7 +418,6 @@ static int pblk_recov_scan_oob(struct pblk *pblk,
>> struct pblk_line *line,
>>       if (ret) {
>>           pblk_err(pblk, "I/O submission failed: %d\n", ret);
>>           bio_put(bio);
>> -        bio_put(bio);
>>           return ret;
>>       }
>>
>
> Thanks Gustavo. I missed that one.
>
> Jens, if possible could you please pick this up?
>
> Happy holidays!
>

Glad to help. :)

Happy holidays everybody.

--
Gustavo

2018-12-23 16:32:06

by Jens Axboe

Subject: Re: [PATCH] lightnvm: pblk: fix use-after-free bug

On 12/22/18 11:30 AM, Matias Bjørling wrote:
> On 12/22/18 8:39 AM, Gustavo A. R. Silva wrote:
>> Remove one of the calls to function bio_put(), so *bio* is only
>> freed once.
>>
>> Notice that bio is being dereferenced in bio_put(), hence leading to
>> a use-after-free bug once *bio* has already been freed.
>>
>> Addresses-Coverity-ID: 1475952 ("Use after free")
>> Fixes: 55d8ec35398e ("lightnvm: pblk: support packed metadata")
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>> drivers/lightnvm/pblk-recovery.c | 1 -
>> 1 file changed, 1 deletion(-)
>>
>> diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
>> index 3fcf062d752c..5ee20da7bdb3 100644
>> --- a/drivers/lightnvm/pblk-recovery.c
>> +++ b/drivers/lightnvm/pblk-recovery.c
>> @@ -418,7 +418,6 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
>> if (ret) {
>> pblk_err(pblk, "I/O submission failed: %d\n", ret);
>> bio_put(bio);
>> - bio_put(bio);
>> return ret;
>> }
>>
>>
>
> Thanks Gustavo. I missed that one.
>
> Jens, if possible could you please pick this up?

Yep, added for the later pull.

--
Jens Axboe