From balagi@justmail.de Sun Oct 22 10:15:45 2006 Date: Sun, 22 Oct 2006 19:17:47 +0200 Subject: sysfs: sysfs_write_file() writes zero terminated data From: "Thomas Maier" Cc: akpm@osdl.org, gregkh@suse.de since most of the files in sysfs are text files, it would be nice, if the "store" function called during sysfs_write_file() gets a zero terminated string / data. The current implementation seems not to ensure this. (But only if it is the first time the zeroed buffer page is allocated.) So the buffer can be scanned by sscanf() easily, for example. This patch simply sets a \0 char behind the data in buffer->page. Signed-off-by: Thomas Maier Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 3 +++ 1 file changed, 3 insertions(+) --- gregkh-2.6.orig/fs/sysfs/file.c +++ gregkh-2.6/fs/sysfs/file.c @@ -190,6 +190,9 @@ fill_write_buffer(struct sysfs_buffer * count = PAGE_SIZE - 1; error = copy_from_user(buffer->page,buf,count); buffer->needs_read_fill = 1; + /* if buf is assumed to contain a string, terminate it by \0, + so e.g. sscanf() can scan the string easily */ + buffer->page[count] = 0; return error ? -EFAULT : count; }