[dm-devel] [PATCH 5.10 1/2] block: split bio_kmalloc from bio_alloc_bioset

[Tadeusz Struk]

On 7/28/22 08:00, Greg KH wrote:
> On Thu, Jul 28, 2022 at 04:45:20PM +0200, Christoph Hellwig wrote:
>> On Thu, Jul 28, 2022 at 04:42:35PM +0200, Greg KH wrote:
>>>>> Link:https://syzkaller.appspot.com/bug?id=a3416231e37024a75f2b95bd95db0d8ce8132a84
>>>> Both now queued up, thanks.
>>> As was just reported, this breaks things all over the place:
>>> 	https://lore.kernel.org/r/219030d8-3408-cc9d-7aec-1fb14ab891ce@roeck-us.net
>>>
>>> Note, I also had to add lots of fix-up patches on top of these two that
>>> you missed, so odds are there are other fix-ups that I also missed.
>>>
>>> Please go and test this again, and submit ALL patches that are needed
>>> after they pass the proper testing and I will be glad to reconsider them
>>> again.
>> Why did this even get backported?  It was a cleanup that required a lot
>> of prep work, and should not by itself fix anything.
> Looks like syzkaller is reporting something odd...
> 
> Tadeusz, how was this tested?

Yes, I tested it with syzbot and locally and it fixed the syzbot reported
"kernel BUG at block/blk-mq.c:567" issue:

https://syzkaller.appspot.com/bug?id=a3416231e37024a75f2b95bd95db0d8ce8132a84

I only tested it with booting from ext4 fs, as I don't have any btrfs setup.

-- 
Thanks,
Tadeusz