NFSv4/pnfs: Fix a use-after-free bug in open

If someone cancels the open RPC call, then we must not try to free either the open slot or the layoutget operation arguments, since they are likely still in use by the hung RPC call. Fixes: 6949493 ("NFSv4: Don't hold the layoutget locks across multiple RPC calls") Signed-off-by: Trond Myklebust <[email protected]>
zandrey · Aug 2, 2022 · 2135e5d · 2135e5d
1 parent b1a28f2
commit 2135e5d
Showing 1 changed file with 6 additions and 5 deletions.
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
@@ -3096,12 +3096,13 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata,
 	}
 
 out:
-	if (opendata->lgp) {
-		nfs4_lgopen_release(opendata->lgp);
-		opendata->lgp = NULL;
-	}
-	if (!opendata->cancelled)
+	if (!opendata->cancelled) {
+		if (opendata->lgp) {
+			nfs4_lgopen_release(opendata->lgp);
+			opendata->lgp = NULL;
+		}
 		nfs4_sequence_free_slot(&opendata->o_res.seq_res);
+	}
 	return ret;
 }