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: 37fb3a30b4 ("fuse: fix flock")
Cc: <stable@vger.kernel.org> # v3.1+
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>

This commit is contained in:

Mateusz Jurczyk

2017-06-07 12:26:49 +02:00

committed by

Willy Tarreau

parent 003bea4a70

commit c2ace3043f

1 changed files with 1 additions and 1 deletions

									
										fs/fuse/file.c
									
		+1
		-1
	
												View File
												
				@@ -54,7 +54,7 @@ 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;