Someone could write 0 bytes to /proc/sgi_uv/ptc_statistics,
causing
optstr[count - 1] = '\0';
to write to who-knows-where.
(Andi Kleen noticed this need from a patch I sent for
similar code in the ia64 world (sn2_ptc_proc_write()).)
(count less than zero is not possible here, as count is unsigned)
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
long newmode;
char optstr[64];
- if (count > 64)
+ if (count == 0 || count > sizeof(optstr))
return -EINVAL;
if (copy_from_user(optstr, user, count))
return -EFAULT;