The following commit has been merged in the linux branch: commit d39b7dd1dcbf394a1cb897457c862dafe9a20ac5 Author: Linus Torvalds torvalds@linux-foundation.org Date: Thu Nov 5 10:48:30 2009 -0800

sgi-gru: decrapfiy options_write() function

Not a single line of actual code in the function was really fundamentally correct.

Problems ranged from lack of proper range checking, to removing the last character written (which admittedly is usually '\n'), to not accepting hex numbers even though the 'show' routine would show the data in that format.

This tries to do better.

Acked-by: Michael Buesch mb@bu3sch.de Tested-and-acked-by: Jack Steiner steiner@sgi.com Cc: stable@kernel.org Cc: Jiri Kosina jkosina@suse.cz Cc: Michael Gilbert michael.s.gilbert@gmail.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org

diff --git a/drivers/misc/sgi-gru/gruprocfs.c b/drivers/misc/sgi-gru/gruprocfs.c index ccd4408..3f2375c 100644 --- a/drivers/misc/sgi-gru/gruprocfs.c +++ b/drivers/misc/sgi-gru/gruprocfs.c @@ -161,14 +161,15 @@ static int options_show(struct seq_file *s, void *p) static ssize_t options_write(struct file *file, const char __user *userbuf, size_t count, loff_t *data) { - unsigned long val; - char buf[80]; + char buf[20];

- if (strncpy_from_user(buf, userbuf, sizeof(buf) - 1) < 0) + if (count >= sizeof(buf)) + return -EINVAL; + if (copy_from_user(buf, userbuf, count)) return -EFAULT; - buf[count - 1] = '\0'; - if (!strict_strtoul(buf, 10, &val)) - gru_options = val; + buf[count] = '\0'; + if (strict_strtoul(buf, 0, &gru_options)) + return -EINVAL;

return count; }