The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 64e6304169f1e1f078e7f0798033f80a7fb0ea46 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2024011244-clavicle-disfigure-47f6@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: 64e6304169f1 ("nfsd: drop the nfsd_put helper") 2a501f55cd64 ("nfsd: call nfsd_last_thread() before final nfsd_put()") 9f28a971ee9f ("nfsd: separate nfsd_last_thread() from nfsd_put()") c034203b6a9d ("nfsd: fix double fget() bug in __write_ports_addfd()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 64e6304169f1e1f078e7f0798033f80a7fb0ea46 Mon Sep 17 00:00:00 2001 From: Jeff Layton <jlayton@xxxxxxxxxx> Date: Wed, 3 Jan 2024 08:36:52 -0500 Subject: [PATCH] nfsd: drop the nfsd_put helper 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> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 05b55db33424..25b5863bf3c8 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 {
