From: Jeff Layton <jlayton@xxxxxxxxxx>
[ Upstream commit 64e6304169f1e1f078e7f0798033f80a7fb0ea46 ]
It's not safe to call nfsd_put once nfsd_last_thread has been called, as
that function will zero out the nn->nfsd_serv pointer.
Drop the nfsd_put helper altogether and open-code the svc_put in its
callers instead. That allows us to not be reliant on the value of that
pointer when handling an error.
Fixes: 2a501f55cd64 ("nfsd: call nfsd_last_thread() before final nfsd_put()")
Reported-by: Zhi Li <yieli@xxxxxxxxxx>
Cc: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Jeffrey Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfsd/nfsctl.c | 31 +++++++++++++++++--------------
fs/nfsd/nfsd.h | 7 -------
2 files changed, 17 insertions(+), 21 deletions(-)
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -709,6 +709,7 @@ static ssize_t __write_ports_addfd(char
char *mesg = buf;
int fd, err;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+ struct svc_serv *serv;
err = get_int(&mesg, &fd);
if (err != 0 || fd < 0)
@@ -718,15 +719,15 @@ static ssize_t __write_ports_addfd(char
if (err != 0)
return err;
- err = svc_addsock(nn->nfsd_serv, net, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
+ serv = nn->nfsd_serv;
+ err = svc_addsock(serv, net, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
- if (err < 0 && !nn->nfsd_serv->sv_nrthreads && !nn->keep_active)
+ if (err < 0 && !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);
+ else if (err >= 0 && !serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
+ svc_get(serv);
- nfsd_put(net);
+ svc_put(serv);
return err;
}
@@ -740,6 +741,7 @@ static ssize_t __write_ports_addxprt(cha
struct svc_xprt *xprt;
int port, err;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+ struct svc_serv *serv;
if (sscanf(buf, "%15s %5u", transport, &port) != 2)
return -EINVAL;
@@ -751,32 +753,33 @@ static ssize_t __write_ports_addxprt(cha
if (err != 0)
return err;
- err = svc_xprt_create(nn->nfsd_serv, transport, net,
+ serv = nn->nfsd_serv;
+ err = svc_xprt_create(serv, transport, net,
PF_INET, port, SVC_SOCK_ANONYMOUS, cred);
if (err < 0)
goto out_err;
- err = svc_xprt_create(nn->nfsd_serv, transport, net,
+ err = svc_xprt_create(serv, transport, net,
PF_INET6, port, SVC_SOCK_ANONYMOUS, cred);
if (err < 0 && err != -EAFNOSUPPORT)
goto out_close;
- if (!nn->nfsd_serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
- svc_get(nn->nfsd_serv);
+ if (!serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
+ svc_get(serv);
- nfsd_put(net);
+ svc_put(serv);
return 0;
out_close:
- xprt = svc_find_xprt(nn->nfsd_serv, transport, net, PF_INET, port);
+ xprt = svc_find_xprt(serv, transport, net, PF_INET, port);
if (xprt != NULL) {
svc_xprt_close(xprt);
svc_xprt_put(xprt);
}
out_err:
- if (!nn->nfsd_serv->sv_nrthreads && !nn->keep_active)
+ if (!serv->sv_nrthreads && !nn->keep_active)
nfsd_last_thread(net);
- nfsd_put(net);
+ svc_put(serv);
return err;
}
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -97,13 +97,6 @@ int nfsd_pool_stats_open(struct inode *
int nfsd_pool_stats_release(struct inode *, struct file *);
void nfsd_shutdown_threads(struct net *net);
-static inline void nfsd_put(struct net *net)
-{
- struct nfsd_net *nn = net_generic(net, nfsd_net_id);
-
- svc_put(nn->nfsd_serv);
-}
-
bool i_am_nfsd(void);
struct nfsdfs_client {
Patches currently in stable-queue which might be from cel@xxxxxxxxxx are
queue-6.1/nfsd-simplify-code-around-svc_exit_thread-call-in-nfsd.patch
queue-6.1/nfsd-separate-nfsd_last_thread-from-nfsd_put.patch
queue-6.1/nfsd-simplify-error-paths-in-nfsd_svc.patch
queue-6.1/nfsd-fix-a-regression-in-nfsd_setattr.patch
queue-6.1/nfsd-drop-the-nfsd_put-helper.patch
queue-6.1/nfsd-call-nfsd_last_thread-before-final-nfsd_put.patch
queue-6.1/nfsd-don-t-call-locks_release_private-twice-concurrently.patch
