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

From: Jens Axboe
Date: Sat Dec 22 2018 - 16:46:01 EST


On 12/22/18 11:30 AM, Matias BjÃrling 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 <gustavo@xxxxxxxxxxxxxx>
>> ---
>> 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