Commit 33bc00a5 authored by Christian Brauner's avatar Christian Brauner Committed by Greg Kroah-Hartman

sysctl: return -EINVAL if val violates minmax

[ Upstream commit e260ad01 ]

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.ioSigned-off-by: default avatarChristian Brauner <christian@brauner.io>
Acked-by: default avatarLuis 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent cafeee0e
......@@ -2874,8 +2874,10 @@ 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;
......
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