From: Mateusz Jurczyk <mjurczyk@google.com>
Date: Wed, 7 Jun 2017 12:26:49 +0200
Subject: [PATCH] fuse: initialize the flock flag in fuse_file on allocation
References: bnc#1060662
Patch-mainline: 4.12.8
Git-commit: 68227c03cba84a24faf8a7277d2b1a03c8959c2c

commit 68227c03cba84a24faf8a7277d2b1a03c8959c2c upstream.

Before the patch, the flock flag could remain uninitialized for the
lifespan of the fuse_file allocation. Unless set to true in
fuse_file_flock(), it would remain in an indeterminate state until read in
an if statement in fuse_release_common(). This could consequently lead to
taking an unexpected branch in the code.

The bug was discovered by a runtime instrumentation designed to detect use
of uninitialized memory in the kernel.

Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Fixes: 37fb3a30b462 ("fuse: fix flock")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 fs/fuse/file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 3ee4fdc3da9e..76eac2a554c4 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -46,7 +46,7 @@ struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
 {
 	struct fuse_file *ff;
 
-	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
+	ff = kzalloc(sizeof(struct fuse_file), GFP_KERNEL);
 	if (unlikely(!ff))
 		return NULL;
 
-- 
2.14.2