Re: [PATCH v5] nvme/069: add a test for multipath cdev lifetime

Shin'ichiro Kawasaki <[email protected]> Thu, 23 Jul 2026 19:05:11 +0900
Newsgroups org.infradead.lists.linux-nvme,org.kernel.vger.linux-block
Message-ID <amHnLkkhLqIPiMHh@shinhome>
On Jul 20, 2026 / 15:02, John Garry wrote:
> From: John Garry <[email protected]>
> 
> In [0], a fix was proposed for the NS and NS head (multipath) cdev
> lifetime.
> 
> The issue was that fds for the nvme-generic cdev may exist after we tear
> down the nvme-subsystem. Issuing an ioctl on that cdev may expose a
> use-after-free.
> 
> This test recreates the method described in [0] to expose this issue
> for NS head cdev.
> 
> First a fd is created by opening the nvme-generic cdev. Next we tear down
> the nvme-subsystem. Finally we try to issue an ioctl on the cdev - without
> the kernel fix in [0], this should trigger a KASAN warn.
> 
> [0] https://lore.kernel.org/linux-nvme/[email protected]/T/#me118851584fbcbb960795d0f04e2262e5a295613
> 
> Reviewed-by: Daniel Wagner <[email protected]>
> Signed-off-by: John Garry <[email protected]>

I applied the patch. Thanks!