On 4/27/21 2:37 PM, Jens Axboe wrote: > On 4/27/21 6:51 AM, Palash Oswal wrote: >> syzkaller identified KASAN: null-ptr-deref Write in >> io_uring_cancel_sqpoll on v5.12 >> >> io_uring_cancel_sqpoll is called by io_sq_thread before calling >> io_uring_alloc_task_context. This leads to current->io_uring being >> NULL. io_uring_cancel_sqpoll should not have to deal with threads >> where current->io_uring is NULL. >> >> In order to cast a wider safety net, perform input sanitisation >> directly in io_uring_cancel_sqpoll and return for NULL value of >> current->io_uring. > > Thanks applied - I augmented the commit message a bit. btw, does it fixes the replied before syz report? Should syz fix or tag it if so. Reported-by: syzbot+be51ca5a4d97f017cd50@xxxxxxxxxxxxxxxxxxxxxxxxx -- Pavel Begunkov
