From 52c479697c9b73f628140dcdfcd39ea302d05482 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat Aug 22 18:25:52 2020 -0400
Subject: [PATCH] do_epoll_ctl(): clean the failure exits up a bit 
Git-commit: 52c479697c9b73f628140dcdfcd39ea302d05482
References: bsc#1180031,CVE-2020-0466
Patch-mainline: v5.9-rc2


Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>

---
 fs/eventpoll.c |   10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -2182,10 +2182,8 @@
 			mutex_lock(&epmutex);
 			if (is_file_epoll(tf.file)) {
 				error = -ELOOP;
-				if (ep_loop_check(ep, tf.file) != 0) {
-					clear_tfile_check_list();
+				if (ep_loop_check(ep, tf.file) != 0)
 					goto error_tgt_fput;
-				}
 			} else {
 				get_file(tf.file);
 				list_add(&tf.file->f_tfile_llink,
@@ -2214,8 +2212,6 @@
 			error = ep_insert(ep, &epds, tf.file, fd, full_check);
 		} else
 			error = -EEXIST;
-		if (full_check)
-			clear_tfile_check_list();
 		break;
 	case EPOLL_CTL_DEL:
 		if (epi)
@@ -2238,8 +2234,10 @@
 	mutex_unlock(&ep->mtx);
 
 error_tgt_fput:
-	if (full_check)
+	if (full_check) {
+		clear_tfile_check_list();
 		mutex_unlock(&epmutex);
+	}
 
 	fdput(tf);
 error_fput: