6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: NeilBrown <neilb@xxxxxxx>
[ Upstream commit 2a501f55cd641eb4d3c16a2eab0d678693fac663 ]
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: ec52361df99b ("SUNRPC: stop using ->sv_nrthreads as a refcount")
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/nfsd/nfsctl.c | 9 +++++++--
fs/nfsd/nfsd.h | 1 +
fs/nfsd/nfssvc.c | 2 +-
3 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 573de0d49e172..b3b4542e31ed5 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -716,8 +716,10 @@ 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);
@@ -767,6 +769,9 @@ 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;
}
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index fddd70372e4cb..53166cce7062c 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -139,6 +139,7 @@ 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;
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 6ac18399fed2b..d8662bdca5706 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -523,7 +523,7 @@ 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;
--
2.43.0
