Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

sysctl: return -EINVAL if val violates minmax

Browse source 
[ Upstream commit e260ad01f0aa9e96b5386d5cd7184afd949dc457 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Christian Brauner 2019-05-14 15:44:55 -07:00 committed by Greg Kroah-Hartman
parent 5b6619b4d2
commit 91ae202e2c
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

@ -2791,8 +2791,10 @@ 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;