Re: BUG: divide error in ubi_attach_mtd_dev

[Yu Hao]

On Thu, Apr 20, 2023 at 10:33 AM Richard Weinberger <richard@xxxxxx> wrote:
>
> ----- Ursprüngliche Mail -----
> > The kernel is in qemu. We find that the `mtd` is from
> > `mtd = get_mtd_device(NULL, req.mtd_num);` in function `ctrl_cdev_ioctl`.
> > And we are still trying to figure out what MTD is.
>
> Can you please share the qemu command line?
>

qemu-system-x86_64 -m 2G -smp 2 -kernel
/home/test/Workspace/SyzGen/linux-distro/linux-6.2-debug/arch/x86/boot/bzImage
-append “console=ttyS0 root=/dev/sda net.ifnames=0” -hda
/home/test/Workspace/SyzGen/linux-distro/image/stretch.img -chardev
socket,id=SOCKSYZ,server=on,nowait,host=localhost,port=54640 -mon
chardev=SOCKSYZ,mode=control -device virtio-rng-pci -device
e1000,netdev=net0 -netdev
user,id=net0,restrict=on,hostfwd=tcp:127.0.0.1:11760-:22 -display none
-serial stdio -cpu host,migratable=off -no-reboot -name VM -snapshot
-enable-kvm

> Within Linux you can query /proc/mtd or /sys/class/mtd/
> to get infos about the MTD in question.
>

Thanks for the hints. We find that this is a “mtdram test device”.

root@syzkaller:~# cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00020000 00001000 “mtdram test device”

> Thanks,
> //richard
>