From 5d9463333714b60aa9c5744e8bca7060e7eb36e2 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 4 Mar 2019 15:34:37 +0000 Subject: [PATCH] rpc: properly check debugfs dentry before using it mainline inclusion from mainline-v5.0-rc7 commit ad6fef776927 category: bugfix bugzilla: 10735 CVE: NA ------------------------------------------------- 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 Signed-off-by: Lin Miaohe Reviewed-by: Mao Wenan Signed-off-by: Yang Yingliang --- 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; } -- GitLab