From: Chuck Lever <chuck.lever@xxxxxxxxxx>
On Wed, 25 Dec 2024 14:59:04 +0800, Yang Erkun wrote:
> After f8c989a0c89a ("nfsd: release svc_expkey/svc_export with
> rcu_work"), svc_export_put/expkey_put will call path_put with async
> mode. This can lead some unexpected failure:
>
> mkdir /mnt/sda
> mkfs.xfs -f /dev/sda
> echo "/ *(rw,no_root_squash,fsid=0)" > /etc/exports
> echo "/mnt *(rw,no_root_squash,fsid=1)" >> /etc/exports
> exportfs -ra
> service nfs-server start
> mount -t nfs -o vers=4.0 127.0.0.1:/mnt /mnt1
> mount /dev/sda /mnt/sda
> touch /mnt1/sda/file
> exportfs -r
> umount /mnt/sda # failed unexcepted
>
> [...]
Applied to nfsd-testing, thanks!
[1/4] SUNRPC: introduce cache_check_rcu to help check in rcu context
commit: 2f55dbe4e2072c9e99298c6f37473778a98c9107
[2/4] nfsd: no need get cache ref when protected by rcu
commit: c224edca7af028828e2ad866b61d731b5e72b46d
[3/4] SUNRPC: no need get cache ref when protected by rcu
commit: 1b10f0b603c066d81327c163a23c19f01e112366
[4/4] nfsd: fix UAF when access ex_uuid or ex_stats
commit: 2530766492ec7726582bcde44575ec3ff7487cd2
--
Chuck Lever
