Re: [PATCH stable 6.1 0/2] devlink: Fix RCU stall when unregistering a devlink instance

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Oct 15, 2024 at 02:36:23PM +0300, Ido Schimmel wrote:
> Upstream commit c2368b19807a ("net: devlink: introduce "unregistering"
> mark and use it during devlinks iteration") in v6.0 introduced a race
> when unregistering a devlink instance that can result in RCU stalls and
> in the system completely locking up. Exact details and reproducer can be
> found here [1]. The bug was inadvertently fixed in v6.3 by upstream
> commit d77278196441 ("devlink: bump the instance index directly when
> iterating").
> 
> This patchset fixes the bug by backporting the second commit and a
> related dependency from v6.3 to v6.1.y while adjusting them to the
> devlink file structure in v6.1.y (net/devlink/{core.c,devl_internal.h}
> -> net/devlink/leftover.c).
> 
> Tested by running the devlink tests under
> tools/testing/selftests/drivers/net/netdevsim/ and the reproducer
> mentioned in [1].
> 
> [1] https://lore.kernel.org/stable/20241001112035.973187-1-idosch@nvidia.com/
> 
> Jakub Kicinski (2):
>   devlink: drop the filter argument from devlinks_xa_find_get
>   devlink: bump the instance index directly when iterating
> 
>  net/devlink/leftover.c | 40 ++++++++++------------------------------
>  1 file changed, 10 insertions(+), 30 deletions(-)
> 
> -- 
> 2.47.0
> 
> 

Both now queued up, thanks.

greg k-h