4.19-stable review patch. If anyone has any objections, please let me know.
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From: Guoqing Jiang guoqing.jiang@linux.dev
[ Upstream commit d078cbf5c38de83bc31f83c47dcd2184c04a50c7 ]
If not enough buffer space available, but idmap_lookup has triggered lookup_fn which calls cache_get and returns successfully. Then we missed to call cache_put here which pairs with cache_get.
Fixes: ddd1ea563672 ("nfsd4: use xdr_reserve_space in attribute encoding") Signed-off-by: Guoqing Jiang guoqing.jiang@linux.dev Reviwed-by: Jeff Layton jlayton@kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfsd/nfs4idmap.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c index a5bb76593ce72..de6bab641b20c 100644 --- a/fs/nfsd/nfs4idmap.c +++ b/fs/nfsd/nfs4idmap.c @@ -565,6 +565,7 @@ static __be32 idmap_id_to_name(struct xdr_stream *xdr, .id = id, .type = type, }; + __be32 status = nfs_ok; __be32 *p; int ret; struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); @@ -577,12 +578,16 @@ static __be32 idmap_id_to_name(struct xdr_stream *xdr, return nfserrno(ret); ret = strlen(item->name); WARN_ON_ONCE(ret > IDMAP_NAMESZ); + p = xdr_reserve_space(xdr, ret + 4); - if (!p) - return nfserr_resource; - p = xdr_encode_opaque(p, item->name, ret); + if (unlikely(!p)) { + status = nfserr_resource; + goto out_put; + } + xdr_encode_opaque(p, item->name, ret); +out_put: cache_put(&item->h, nn->idtoname_cache); - return 0; + return status; }
static bool