NeilBrown 6e5fed48d8 NFSD: fix possible oops when nfsd/pool_stats is closed.
[ Upstream commit 88956eabfdea7d01d550535af120d4ef265b1d02 ]

If /proc/fs/nfsd/pool_stats is open when the last nfsd thread exits, then
when the file is closed a NULL pointer is dereferenced.
This is because nfsd_pool_stats_release() assumes that the
pointer to the svc_serv cannot become NULL while a reference is held.

This used to be the case but a recent patch split nfsd_last_thread() out
from nfsd_put(), and clearing the pointer is done in nfsd_last_thread().

This is easily reproduced by running
   rpc.nfsd 8 ; ( rpc.nfsd 0;true) < /proc/fs/nfsd/pool_stats

Fortunately nfsd_pool_stats_release() has easy access to the svc_serv
pointer, and so can call svc_put() on it directly.

Fixes: 9f28a971ee9f ("nfsd: separate nfsd_last_thread() from nfsd_put()")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-10 16:19:29 +02:00
..
2024-04-10 16:18:38 +02:00
2024-02-23 08:54:51 +01:00
2021-12-29 12:28:59 +01:00
2024-03-01 13:21:47 +01:00
2023-09-19 12:22:53 +02:00
2024-03-01 13:21:43 +01:00
2023-09-23 11:10:01 +02:00
2023-12-08 08:48:04 +01:00
2023-08-30 16:18:19 +02:00
2024-04-10 16:19:01 +02:00
2022-12-14 11:37:31 +01:00
2023-01-12 11:58:47 +01:00
2022-07-02 16:41:17 +02:00
2022-07-12 16:35:08 +02:00
2021-12-14 10:57:15 +01:00