Re: [PATCH] block: aoe: fix page fault in freedev()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Mar 10, 2022 at 12:53:01PM +0100, Valentin Kleibel wrote:
> There is a bug in the aoe driver module where every forcible removal of an
> aoe device (eg. "rmmod aoe" with aoe devices available or "aoe-flush ex.x")
> leads to a page fault.
> The code in freedev() calls blk_mq_free_tag_set() before running
> blk_cleanup_queue() which leads to this issue (drivers/block/aoe/aoedev.c
> L281ff).
> This issue was fixed upstream in commit 6560ec9 (aoe: use blk_mq_alloc_disk
> and blk_cleanup_disk) with the introduction and use of the function
> blk_cleanup_disk().
> 
> This patch applies to kernels 5.4 and 5.10.

We need a fix for Linus's tree first before we can backport anything to
older kernels.  Does this also work there?

> 
> The function calls are reordered to match the behavior of blk_cleanup_disk()
> to mitigate this issue.
> 
> Fixes: 3582dd2 (aoe: convert aoeblk to blk-mq)

A few more digits in the sha1 here would be good, otherwise our tools
will complain.  It should look like:
Fixes: 3582dd291788 ("aoe: convert aoeblk to blk-mq")

thanks,

greg k-h