Patch "fuse: initialize the flock flag in fuse_file on allocation" has been added to the 3.18-stable tree

Patch "fuse: initialize the flock flag in fuse_file on allocation" has been added to the 3.18-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    fuse: initialize the flock flag in fuse_file on allocation

to the 3.18-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     fuse-initialize-the-flock-flag-in-fuse_file-on-allocation.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 68227c03cba84a24faf8a7277d2b1a03c8959c2c Mon Sep 17 00:00:00 2001
From: Mateusz Jurczyk <mjurczyk@google.com>
Date: Wed, 7 Jun 2017 12:26:49 +0200
Subject: fuse: initialize the flock flag in fuse_file on allocation

From: Mateusz Jurczyk <mjurczyk@google.com>

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>

---
 fs/fuse/file.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -54,7 +54,7 @@ struct fuse_file *fuse_file_alloc(struct
 {
 	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;
 


Patches currently in stable-queue which might be from mjurczyk@google.com are

queue-3.18/fuse-initialize-the-flock-flag-in-fuse_file-on-allocation.patch