openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

sysctl: return -EINVAL if val violates minmax 

Currently when userspace gives us a values that overflow e.g.  file-max
and other callers of __do_proc_doulongvec_minmax() we simply ignore the
new value and leave the current value untouched.

This can be problematic as it gives the illusion that the limit has
indeed be bumped when in fact it failed.  This commit makes sure to
return EINVAL when an overflow is detected.  Please note that this is a
userspace facing change.

Link: http://lkml.kernel.org/r/20190210203943.8227-4-christian@brauner.io
Signed-off-by: Christian Brauner <christian@brauner.io>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christian Brauner 2019-05-14 15:44:55 -07:00 committed by Linus Torvalds
parent 475dae3854
commit e260ad01f0
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
kernel/sysctl.c
View File

@ -2886,8 +2886,10 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
if (neg)
continue;
val = convmul * val / convdiv;
if ((min && val < *min) || (max && val > *max))
continue;
if ((min && val < *min) || (max && val > *max)) {
err = -EINVAL;
break;
}
*i = val;
} else {
val = convdiv * (*i) / convmul;