nfsd: fix double fget() bug in __write_ports_addfd()
authorDan Carpenter <dan.carpenter@linaro.org>
Mon, 29 May 2023 11:35:55 +0000 (14:35 +0300)
committerChuck Lever <chuck.lever@oracle.com>
Wed, 31 May 2023 13:57:14 +0000 (09:57 -0400)
commitc034203b6a9dae6751ef4371c18cb77983e30c28
treeac499da052b4a58091c2eb857fdbdeb58ca7f692
parentd53d70084d27f56bcdf5074328f2c9ec861be596
nfsd: fix double fget() bug in __write_ports_addfd()

The bug here is that you cannot rely on getting the same socket
from multiple calls to fget() because userspace can influence
that.  This is a kind of double fetch bug.

The fix is to delete the svc_alien_sock() function and instead do
the checking inside the svc_addsock() function.

Fixes: 3064639423c4 ("nfsd: check passed socket's net matches NFSd superblock's one")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: NeilBrown <neilb@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
fs/nfsd/nfsctl.c
include/linux/sunrpc/svcsock.h
net/sunrpc/svcsock.c