libertas: potential oops in debugfs

If we do a zero size allocation then it will oops.  Also we can't be
sure the user passes us a NUL terminated string so I've added a
terminator.

This code can only be triggered by root.

Reported-by: Nico Golde <nico@ngolde.de>
Reported-by: Fabian Yamaguchi <fabs@goesec.de>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Dan Carpenter 2013-10-30 20:12:51 +03:00 committed by John W. Linville
parent 450991fd2f
commit a497e47d4a

View file

@ -913,7 +913,10 @@ static ssize_t lbs_debugfs_write(struct file *f, const char __user *buf,
char *p2;
struct debug_data *d = f->private_data;
pdata = kmalloc(cnt, GFP_KERNEL);
if (cnt == 0)
return 0;
pdata = kmalloc(cnt + 1, GFP_KERNEL);
if (pdata == NULL)
return 0;
@ -922,6 +925,7 @@ static ssize_t lbs_debugfs_write(struct file *f, const char __user *buf,
kfree(pdata);
return 0;
}
pdata[cnt] = '\0';
p0 = pdata;
for (i = 0; i < num_of_items; i++) {