[Devel] [PATCH vz9 v2 01/11] file: add fput() cleanup helper

[Eva Kurchatova]

From: Christian Brauner <brauner at kernel.org>

[ Upstream commit 257b1c2c78c25643526609dee0c15f1544eb3252 ]

Add a simple helper to put a file reference.

Link: https://lore.kernel.org/r/20240719-work-mount-namespace-v1-4-834113cab0d2@kernel.org
Reviewed-by: Josef Bacik <josef at toxicpanda.com>
Reviewed-by: Jeff Layton <jlayton at kernel.org>
Signed-off-by: Christian Brauner <brauner at kernel.org>
(cherry picked from commit 257b1c2c78c25643526609dee0c15f1544eb3252)
Signed-off-by: Wentao Guan <guanwentao at uniontech.com>
Signed-off-by: Eva Kurchatova <eva.kurchatova at virtuozzo.com>

https://virtuozzo.atlassian.net/browse/VSTOR-137490
Feature: fix epoll cve
---
 include/linux/file.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/file.h b/include/linux/file.h
index 5f28fdb297e2..591c99afc854 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -11,6 +11,7 @@
 #include <linux/posix_types.h>
 #include <linux/errno.h>
 #include <linux/cleanup.h>
+#include <linux/err.h>
 
 struct file;
 
@@ -97,6 +98,7 @@ extern void put_unused_fd(unsigned int fd);
 
 DEFINE_CLASS(get_unused_fd, int, if (_T >= 0) put_unused_fd(_T),
 	     get_unused_fd_flags(flags), unsigned flags)
+DEFINE_FREE(fput, struct file *, if (!IS_ERR_OR_NULL(_T)) fput(_T))
 
 extern void fd_install(unsigned int fd, struct file *file);
 
-- 
2.55.0