p9_client_readdir() fix

commit 71d6ad0 upstream. Don't assume that server is sane and won't return more data than asked for. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
lordarcadius · May 8, 2017 · 1c755e1 · 1c755e1
1 parent 91f5719
commit 1c755e1
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/net/9p/client.c b/net/9p/client.c
@@ -2106,6 +2106,10 @@ int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
 		trace_9p_protocol_dump(clnt, req->rc);
 		goto free_and_error;
 	}
+	if (rsize < count) {
+		pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
+		count = rsize;
+	}
 
 	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);