1
linux/fs/sysfs
Miao Xie 8118a859dc sysfs: fix off-by-one error in fill_read_buffer()
I found that there is a off-by-one problem in the following code.

Version:	2.6.24-rc2
File:		fs/sysfs/file.c:118-122
Function:	fill_read_buffer
--------------------------------------------------------------------
	count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page);

	sysfs_put_active_two(attr_sd);

	BUG_ON(count > (ssize_t)PAGE_SIZE);
--------------------------------------------------------------------

Because according to the specification of the sysfs and the implement of
the show methods, the show methods return the number of bytes which would
be generated for the given input, excluding the trailing null.So if the
return value of the show methods equals PAGE_SIZE - 1, the buffer is full
in fact.  And if the return value equals PAGE_SIZE, the resulting string
was already truncated,or buffer overflow occurred.

This patch fixes an off-by-one error in fill_read_buffer.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tejun Heo <teheo@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-11-28 13:53:53 -08:00
..
bin.c sysfs: add copyrights 2007-10-12 14:51:12 -07:00
dir.c sysfs: make sysfs_{get,put}_active() static 2007-10-30 21:52:33 -07:00
file.c sysfs: fix off-by-one error in fill_read_buffer() 2007-11-28 13:53:53 -08:00
group.c sysfs: Remove first pass at shadow directory support 2007-10-12 14:51:03 -07:00
inode.c mm: bdi init hooks 2007-10-17 08:42:45 -07:00
Makefile
mount.c mm: bdi init hooks 2007-10-17 08:42:45 -07:00
symlink.c sysfs: add copyrights 2007-10-12 14:51:12 -07:00
sysfs.h sysfs: make sysfs_{get,put}_active() static 2007-10-30 21:52:33 -07:00