This is a note to let you know that I've just added the patch titled
nfsd: call cache_put if xdr_reserve_space returns NULL
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsd-call-cache_put-if-xdr_reserve_space-returns-nul.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9bc910840fe92b7a687f153f7138bdae8fa3dcca
Author: Guoqing Jiang <guoqing.jiang@xxxxxxxxx>
Date: Wed Aug 21 22:03:18 2024 +0800
nfsd: call cache_put if xdr_reserve_space returns NULL
[ 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@xxxxxxxxx>
Reviwed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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
