From 1f3d09306bf5d3572c0cda033a4c83603216c598 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Sun, 18 Apr 2021 19:09:30 +0300 Subject: [PATCH] sysctl_handle_string: do not malloc when SYSCTL_IN cannot fault (cherry picked from commit 4342ba184c15f3b8912e95f93fe313731963f065) --- sys/kern/kern_sysctl.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c index ffb6ac196ba..4bfe7073e5a 100644 --- a/sys/kern/kern_sysctl.c +++ b/sys/kern/kern_sysctl.c @@ -1785,6 +1785,15 @@ sysctl_handle_string(SYSCTL_HANDLER_ARGS) sx_xlock(&sysctlstringlock); ((char *)arg1)[0] = '\0'; sx_xunlock(&sysctlstringlock); + } else if (req->newfunc == sysctl_new_kernel) { + arg2 = req->newlen - req->newidx; + sx_xlock(&sysctlstringlock); + error = SYSCTL_IN(req, arg1, arg2); + if (error == 0) { + ((char *)arg1)[arg2] = '\0'; + req->newidx += arg2; + } + sx_xunlock(&sysctlstringlock); } else { arg2 = req->newlen - req->newidx; tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);