Re: kintegrityd workqueue fix backported, but only to some LTS

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Mar 14, 2022 at 11:50:18AM +0000, Niklas Cassel wrote:
> Hello Christoph, stable,
> 
> I recently saw a crash caused by the kintegrityd workqueue that could only
> be reproduced on older kernels.
> A null pointer dereference in function bio_integrity_verify_fn.
> 
> The fix in Linus's tree for this:
> 3df49967f6f1 ("block: flush the integrity workqueue in blk_integrity_unregister")
> was first merged in v5.15.
> 
> The fix has been backported to v5.10 LTS branch in:
> 1ef68b84bc11 ("block: flush the integrity workqueue in blk_integrity_unregister")
> 
> The fix doesn't have a fixes tag, but from inspecting the code,
> I don't understand why this was only backported to v5.10, AFAICT it should
> at least have been backported to v5.4, v4.19 and v4.14 LTS as well.
> 
> Original series:
> https://lore.kernel.org/all/20210914070657.87677-3-hch@lst.de/
> 
> The blk_flush_integrity() call that actually fixes the crash should be
> trivial to backport/add before clearing the flag and doing the memset.

A backported patch series would be great to have, to show that you have
tested that it works properly.

thanks,

greg k-h