ACK: [SRU][N][PATCH 0/1] CVE-2024-56672

[Koichiro Den]

On Mon, Feb 10, 2025 at 02:37:14PM GMT, Massimiliano Pellizzer wrote:
> [Impact]
> 
> blk-cgroup: Fix UAF in blkcg_unpin_online()
> 
> blkcg_unpin_online() walks up the blkcg hierarchy putting the online pin. To
> walk up, it uses blkcg_parent(blkcg) but it was calling that after
> blkcg_destroy_blkgs(blkcg) which could free the blkcg, leading to a UAF.
> 
> Fix it by reading the parent pointer before destroying the blkcg's blkg's.
> 
> [Fix]
> 
> Oracular: Fixed via upstream stable updates (LP: #2097332)
> Noble: Cherry picked from mainline
> Jammy: Fixed via upstream stable updates (LP: #2097298)
> Focal: Not affected
> 
> [Test case]
> 
> Compile tested only.
> 
> [Where problems could occur]
> 
> A regression here is unlikely due to the very limited scope of the
> patch.
> 
> Tejun Heo (1):
>   blk-cgroup: Fix UAF in blkcg_unpin_online()
> 
>  block/blk-cgroup.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 

Acked-by: Koichiro Den <koichiro.den at canonical.com>