From: NeilBrown Date: Fri, 18 Jul 2025 01:26:14 +0000 (+1000) Subject: nfsd: avoid ref leak in nfsd_open_local_fh() X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=e5a73150776f18547ee685c9f6bfafe549714899;p=users%2Fjedix%2Flinux-maple.git nfsd: avoid ref leak in nfsd_open_local_fh() If two calls to nfsd_open_local_fh() race and both successfully call nfsd_file_acquire_local(), they will both get an extra reference to the net to accompany the file reference stored in *pnf. One of them will fail to store (using xchg()) the file reference in *pnf and will drop that reference but WON'T drop the accompanying reference to the net. This leak means that when the nfs server is shut down it will hang in nfsd_shutdown_net() waiting for &nn->nfsd_net_free_done. This patch adds the missing nfsd_net_put(). Reported-by: Mike Snitzer Fixes: e6f7e1487ab5 ("nfs_localio: simplify interface to nfsd for getting nfsd_file") Cc: stable@vger.kernel.org Signed-off-by: NeilBrown Tested-by: Mike Snitzer Reviewed-by: Mike Snitzer Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- diff --git a/fs/nfsd/localio.c b/fs/nfsd/localio.c index 4f6468eb2adf6..cb237f1b902a7 100644 --- a/fs/nfsd/localio.c +++ b/fs/nfsd/localio.c @@ -103,10 +103,11 @@ nfsd_open_local_fh(struct net *net, struct auth_domain *dom, if (nfsd_file_get(new) == NULL) goto again; /* - * Drop the ref we were going to install and the - * one we were going to return. + * Drop the ref we were going to install (both file and + * net) and the one we were going to return (only file). */ nfsd_file_put(localio); + nfsd_net_put(net); nfsd_file_put(localio); localio = new; }