nfsd: call nfsd_last_thread() before final nfsd_put()

If write_ports_addfd or write_ports_addxprt fail, they call nfsd_put()
without calling nfsd_last_thread().  This leaves nn->nfsd_serv pointing
to a structure that has been freed.

So remove 'static' from nfsd_last_thread() and call it when the
nfsd_serv is about to be destroyed.

Fixes: ec52361df9 ("SUNRPC: stop using ->sv_nrthreads as a refcount")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
NeilBrown 2023-12-15 11:56:31 +11:00 committed by Chuck Lever
parent bf51c52a1f
commit 2a501f55cd
3 changed files with 9 additions and 3 deletions

View file

@ -705,8 +705,10 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred
err = svc_addsock(nn->nfsd_serv, net, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
if (err >= 0 &&
!nn->nfsd_serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
if (err < 0 && !nn->nfsd_serv->sv_nrthreads && !nn->keep_active)
nfsd_last_thread(net);
else if (err >= 0 &&
!nn->nfsd_serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
svc_get(nn->nfsd_serv);
nfsd_put(net);
@ -757,6 +759,9 @@ static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cr
svc_xprt_put(xprt);
}
out_err:
if (!nn->nfsd_serv->sv_nrthreads && !nn->keep_active)
nfsd_last_thread(net);
nfsd_put(net);
return err;
}

View file

@ -155,6 +155,7 @@ int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change);
int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change);
void nfsd_reset_versions(struct nfsd_net *nn);
int nfsd_create_serv(struct net *net);
void nfsd_last_thread(struct net *net);
extern int nfsd_max_blksize;

View file

@ -542,7 +542,7 @@ static struct notifier_block nfsd_inet6addr_notifier = {
/* Only used under nfsd_mutex, so this atomic may be overkill: */
static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
static void nfsd_last_thread(struct net *net)
void nfsd_last_thread(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct svc_serv *serv = nn->nfsd_serv;