Date: Sun, 8 May 2005 15:45:00 +0200 From: Hans Petter Selasky <hselasky@c2i.net> To: FreeBSD-gnats-submit@FreeBSD.org Subject: kern/80775: sysctl_handle_string should have a timeout Message-ID: <200505081545.01840.hselasky@c2i.net> Resent-Message-ID: <200505081350.j48Do3Gb004291@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
>Number: 80775
>Category: kern
>Synopsis: sysctl_handle_string should have a timeout
>Confidential: no
>Severity: critical
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sun May 08 13:50:02 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator: HPS
>Release: FreeBSD 6.0-CURRENT i386
>Organization:
>Environment:
System: FreeBSD 6.0-CURRENT FreeBSD 6.0-CURRENT #45: Mon Mar 21 15:40:17 CET
2005 root@:/usr/obj/usr/src/sys/custom i386
>Description:
File: /sys/kern/kern_sysctl.c
int
sysctl_handle_string(SYSCTL_HANDLER_ARGS)
{
int error=0;
char *tmparg;
size_t outlen;
/*
* Attempt to get a coherent snapshot by copying to a
* temporary kernel buffer.
*/
retry:
outlen = strlen((char *)arg1)+1;
tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK);
if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) {
free(tmparg, M_SYSCTLTMP);
goto retry;
}
error = SYSCTL_OUT(req, tmparg, outlen);
free(tmparg, M_SYSCTLTMP);
When a device detaches strings can be left in freed memory, so
"sysctl_handle_string" shouldn't try forever. Also the thread updating the
string can sleep.
>How-To-Repeat:
>Fix:
Should have a timeout count and something like:
u_int8_t to = 255;
if(to--)
goto retry;
else return EINVAL;
>Release-Note:
>Audit-Trail:
>Unformatted:
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200505081545.01840.hselasky>