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> --- I know it's late, but it would be good to get this into v6.7 if possible. I think it's fairly straightforward. --- fs/nfsd/nfsctl.c | 31 +++++++++++++++++-------------- fs/nfsd/nfsd.h | 7 ------- 2 files changed, 17 insertions(+), 21 deletions(-) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 7cd513e59305..87fed75808ff 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -693,6 +693,7 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred 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) @@ -703,15 +704,15 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred 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; } @@ -725,6 +726,7 @@ static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cr 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; @@ -737,32 +739,33 @@ static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cr 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; } diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index 3286ffacbc56..9ed0e08d16c2 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -113,13 +113,6 @@ int nfsd_pool_stats_open(struct inode *, struct file *); 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 { --- base-commit: 610a9b8f49fbcf1100716370d3b5f6f884a2835a change-id: 20240103-nfsd-fixes-1f1196134a11 Best regards, -- Jeff Layton <jlayton@xxxxxxxxxx>