6.6-stable review patch. If anyone has any objections, please let me know.
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From: NeilBrown neilb@suse.de
commit 2a501f55cd641eb4d3c16a2eab0d678693fac663 upstream.
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@suse.de Reviewed-by: Jeff Layton jlayton@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfsd/nfsctl.c | 9 +++++++-- fs/nfsd/nfsd.h | 1 + fs/nfsd/nfssvc.c | 2 +- 3 files changed, 9 insertions(+), 3 deletions(-)
--- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -704,8 +704,10 @@ static ssize_t __write_ports_addfd(char
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); @@ -756,6 +758,9 @@ out_close: svc_xprt_put(xprt); } out_err: + if (!nn->nfsd_serv->sv_nrthreads && !nn->keep_active) + nfsd_last_thread(net); + nfsd_put(net); return err; } --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -138,6 +138,7 @@ int nfsd_vers(struct nfsd_net *nn, int v 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;
--- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -542,7 +542,7 @@ static struct notifier_block nfsd_inet6a /* 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;