Commit c68a027c authored Nov 20, 2015 by Benjamin Coddington Committed by Trond Myklebust Nov 23, 2015

nfs4: start callback_ident at idr 1



If clp->cl_cb_ident is zero, then nfs_cb_idr_remove_locked() skips removing
it when the nfs_client is freed.  A decoding or server bug can then find
and try to put that first nfs_client which would lead to a crash.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Fixes: d6870312 ("nfs4client: convert to idr_alloc()")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

parent 91ab4b4d

fs/nfs/nfs4client.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -33,7 +33,7 @@ static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
		return ret;
		idr_preload(GFP_KERNEL);
		spin_lock(&nn->nfs_client_lock);
		ret = idr_alloc(&nn->cb_ident_idr, clp, 0, 0, GFP_NOWAIT);
		ret = idr_alloc(&nn->cb_ident_idr, clp, 1, 0, GFP_NOWAIT);
		if (ret >= 0)
		clp->cl_cb_ident = ret;
		spin_unlock(&nn->nfs_client_lock);

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