From: Mateusz Jurczyk <mjurczyk@google.com>
Date: Wed, 7 Jun 2017 10:26:49 +0000 (+0200)
Subject: fuse: initialize the flock flag in fuse_file on allocation
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=76a3bcccbb04338180475763cbef6128f040a065;p=pandora-kernel.git

fuse: initialize the flock flag in fuse_file on allocation

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: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 1f78f91dedc4..7be47190c3fd 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -52,7 +52,7 @@ 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;