From ad6fef776927b4172e55a1bd97b3cd441a0c261c Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 12 Feb 2019 19:27:34 +0100 Subject: [PATCH] rpc: properly check debugfs dentry before using it debugfs can now report an error code if something went wrong instead of just NULL. So if the return value is to be used as a "real" dentry, it needs to be checked if it is an error before dereferencing it. This is now happening because of ff9fb72bc077 ("debugfs: return error values, not NULL"), but why debugfs files are not being created properly is an older issue, probably one that has always been there and should probably be looked at... Cc: "J. Bruce Fields" Cc: Jeff Layton Cc: Trond Myklebust Cc: Anna Schumaker Cc: linux-nfs@vger.kernel.org Cc: netdev@vger.kernel.org Reported-by: David Howells Tested-by: David Howells Signed-off-by: Greg Kroah-Hartman Signed-off-by: Anna Schumaker --- net/sunrpc/debugfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c index 45a033329cd4..19bb356230ed 100644 --- a/net/sunrpc/debugfs.c +++ b/net/sunrpc/debugfs.c @@ -146,7 +146,7 @@ rpc_clnt_debugfs_register(struct rpc_clnt *clnt) rcu_read_lock(); xprt = rcu_dereference(clnt->cl_xprt); /* no "debugfs" dentry? Don't bother with the symlink. */ - if (!xprt->debugfs) { + if (IS_ERR_OR_NULL(xprt->debugfs)) { rcu_read_unlock(); return; }