From: Greg Kroah-Hartman Date: Tue, 12 Feb 2019 18:27:34 +0000 (+0100) Subject: rpc: properly check debugfs dentry before using it X-Git-Tag: v5.0-rc7~11^2~1 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=ad6fef776927b4172e55a1bd97b3cd441a0c261c;p=linux.git 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 --- 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; }