Commit 68227c03 authored Jun 07, 2017 by Mateusz Jurczyk Committed by Miklos Szeredi Jun 09, 2017

fuse: initialize the flock flag in fuse_file on allocation



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: 37fb3a30 ("fuse: fix flock")
Cc: <stable@vger.kernel.org> # v3.1+
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

parent 2ea659a9

fs/fuse/file.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;

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