Re: KASAN: use-after-free in move_expired_inodes

[Shankara Pailoor]

Hi Al, etc,

I was unable to find a reproducer but I was looking at
move_expired_inodes (fs/fs-writeback.c 1093.c) and how do you ensure
that the inode can't be freed after retrieving it from the work queue?
Any insights would be appreciated.

Regards,
Shankara

On Tue, Oct 31, 2017 at 9:24 AM, Shankara Pailoor <sp3485@xxxxxxxxxxxx> wrote:
> Hi,
>
> We got the following error:
>
> BUG: KASAN: use-after-free in move_expired_inodes+0xce6/0xdf0
> Write of size 8 at addr ffff8800a3a36bf8 by task kworker/u8:0/5
>
> while fuzzing with Syzkaller on 4.14-rc4 on x86_64. Included is the
> trace of the crash along with the programs running around the time of
> the crash.
>
> Programs can be found here: https://pastebin.com/RYGtNn3z
>
> Stack trace here: https://pastebin.com/SaJXWMg3
>
> We don't have a C reproducer but we will send one if we have it.
>
> Regards,
> Shankara