stapelberg

(dlv) b main.main
Breakpoint 1 set at 0x48004e for main.main() ./debugme.go:5
(dlv) c
> main.main() ./debugme.go:5 (hits goroutine(1):1 total:1) (PC: 0x48004e)
     1:	package main
     2:	
     3:	import "os"
     4:	
=>   5:	func main() {
     6:		fi, _ := os.Lstat("/this/path/does/not/exist")

stapelberg

// Tailscale Frontend: It uses tailscale-as-a-library to
// listen on a port, independently from the operating system network, i.e. you
// can run an nginx server on :80 and :443 without impacting the frontend.
//
// set up DNS, e.g.:
// prometheus.ts.zekjur.net A 100.117.6.125
//
// frontend% TAILSCALE_USE_WIP_CODE=true tailscalefrontend -hostname=srv.example.net -allowed_user=michael@example.net
//
// (first login requires running with TS_LOGIN=1 environment variable to print link for the browser)

stapelberg

goroutine 43 [running]:
runtime.throw(0x3cd01c, 0x21)
	/home/michael/sdk/go1.16beta1/src/runtime/panic.go:1112 +0x54 fp=0x400004a740 sp=0x400004a710 pc=0x42654
sync.throw(0x3cd01c, 0x21)
	/home/michael/sdk/go1.16beta1/src/runtime/panic.go:1098 +0x30 fp=0x400004a760 sp=0x400004a740 pc=0x71110
sync.(*RWMutex).rUnlockSlow(0x40000acf00, 0xffffffff)
	/home/michael/sdk/go1.16beta1/src/sync/rwmutex.go:93 +0x40 fp=0x400004a790 sp=0x400004a760 pc=0x80a10
sync.(*RWMutex).RUnlock(...)
	/home/michael/sdk/go1.16beta1/src/sync/rwmutex.go:83
html/template.(*Template).wrapFuncs.func1(0x400009e3d8, 0x1, 0x1, 0x0, 0x0, 0x0)

stapelberg

Thread 1 "Xorg" hit Breakpoint 4, miValidateTree (pParent=0x1a960f0, pChild=0x2644a30, kind=<optimized out>)
    at ../../usr/src/xorg-server-amd64-1.20.3-4/mi/mivaltree.c:678
678	        if (pWin->viewable) {
$159 = {drawable = {type = 0 '\000', class = 1 '\001', depth = 24 '\030', bitsPerPixel = 32 ' ', id = 20971521, x = 0, y = 0, width = 3200, height = 79, 
    pScreen = 0x1a71480, serialNumber = 43125}, devPrivates = 0x2644af8, parent = 0x1a960f0, nextSib = 0x26d6d60, prevSib = 0x0, firstChild = 0x0, 
  lastChild = 0x0, clipList = {extents = {x1 = 0, y1 = 79, x2 = 0, y2 = 79}, data = 0x6178a0 <RegionEmptyData>}, borderClip = {extents = {x1 = 0, y1 = 79, 
      x2 = 0, y2 = 79}, data = 0x6178a0 <RegionEmptyData>}, valdata = 0x256f880, winSize = {extents = {x1 = 0, y1 = 0, x2 = 3200, y2 = 79}, data = 0x0}, 
  borderSize = {extents = {x1 = 0, y1 = 0, x2 = 3200, y2 = 79}, data = 0x0}, origin = {x = 0, y = 0}, borderWidth = 0, deliverableEvents = 32847, 
  eventMask = 2326537, background = {pixmap = 0xffffff,

stapelberg

Thread 1 "Xorg" hit Breakpoint 4, miValidateTree (pParent=0x1a960f0, pChild=0x2644a30, kind=<optimized out>)
    at ../../usr/src/xorg-server-amd64-1.20.3-4/mi/mivaltree.c:678
678	        if (pWin->viewable) {
$109 = {drawable = {type = 0 '\000', class = 1 '\001', depth = 24 '\030', bitsPerPixel = 32 ' ', id = 20971521, x = 0, y = 0, width = 3200, height = 79, 
    pScreen = 0x1a71480, serialNumber = 43046}, devPrivates = 0x2644af8, parent = 0x1a960f0, nextSib = 0x2644270, prevSib = 0x0, firstChild = 0x0, 
  lastChild = 0x0, clipList = {extents = {x1 = 0, y1 = 79, x2 = 0, y2 = 79}, data = 0x6178a0 <RegionEmptyData>}, borderClip = {extents = {x1 = 0, y1 = 79, 
      x2 = 0, y2 = 79}, data = 0x6178a0 <RegionEmptyData>}, valdata = 0x273cd20, winSize = {extents = {x1 = 0, y1 = 0, x2 = 3200, y2 = 79}, data = 0x0}, 
  borderSize = {extents = {x1 = 0, y1 = 0, x2 = 3200, y2 = 79}, data = 0x0}, origin = {x = 0, y = 0}, borderWidth = 0, deliverableEvents = 32845, 
  eventMask = 2326537, background = {pixmap = 0xffffff,

stapelberg

Thread 1 "Xorg" hit Breakpoint 2, SendVisibilityNotify (pWin=pWin@entry=0x2644a30) at ../../usr/src/xorg-server-amd64-1.20.3-4/dix/window.c:3035
3035	    unsigned int visibility = pWin->visibility;
(gdb) bt
#0  SendVisibilityNotify (pWin=pWin@entry=0x2644a30) at ../../usr/src/xorg-server-amd64-1.20.3-4/dix/window.c:3035
#1  0x0000000000447818 in miComputeClips (pParent=pParent@entry=0x2644a30, pScreen=pScreen@entry=0x1a71480, universe=universe@entry=0x7ffc5e4f7e10, 
    kind=kind@entry=VTMap, exposed=exposed@entry=0x7ffc5e4f7e30) at ../../usr/src/xorg-server-amd64-1.20.3-4/mi/mivaltree.c:276
#2  0x0000000000447cb7 in miValidateTree (pParent=0x1a960f0, pChild=0x2644a30, kind=<optimized out>)
    at ../../usr/src/xorg-server-amd64-1.20.3-4/mi/mivaltree.c:681
#3  0x000000000048df96 in MapWindow (pWin=0x2644a30, client=client@entry=0x2694100) at ../../usr/src/xorg-server-amd64-1.20.3-4/dix/window.c:2699
#4  0x000000000045e77e in ProcMapWindow (client=0x2694100) at ../../usr/src/xorg-server-amd64-1.20.3-4/dix/disp

stapelberg

(gdb) b SendVisibilityNotify
Breakpoint 2 at 0x48ebe0: file ../../usr/src/xorg-server-amd64-1.20.3-4/dix/window.c, line 3035.
(gdb) c
Continuing.

Thread 1 "Xorg" hit Breakpoint 2, SendVisibilityNotify (pWin=pWin@entry=0x2644a30) at ../../usr/src/xorg-server-amd64-1.20.3-4/dix/window.c:3035
3035	    unsigned int visibility = pWin->visibility;
(gdb) bt
#0  SendVisibilityNotify (pWin=pWin@entry=0x2644a30) at ../../usr/src/xorg-server-amd64-1.20.3-4/dix/window.c:3035
#1  0x0000000000447818 in miComputeClips (pParent=pParent@entry=0x2644a30, pScreen=pScreen@entry=0x1a71480, universe=universe@entry=0x7ffc5e4f7e10, 

stapelberg

I did the following analysis on the status of publicly reported security
vulnerabilities in info-zip, the unzip implementation used by all major Linux
distributions (as well as OpenBSD and NetBSD).

| CVE              | impact | debian | rhel    | fedora | arch  | gentoo | OpenBSD |
| CVE-2018-18384   | (n/a)  | fixed  | vuln    | fixed  | fixed | fixed  | vuln    |
| CVE-2018-1000035 | high   | vuln   | wontfix | fixed  | vuln  | vuln   | vuln    |
| CVE-2016-9844    | medium | fixed  | wontfix | fixed  | fixed | fixed  | vuln    |

Disclaimer: some distributions might have system-wide protections against some

stapelberg

~ % mkdir /tmp/apt
~ % cd /tmp/apt
/tmp/apt % cat > apt.go <<'EOT'
package main

import (
	"bytes"
	"log"

	"github.com/stapelberg/godebiancontrol"

stapelberg

// Binary squashvrfy creates squashfs file system images using the gokrazy
// squashfs writer, then verifies that the resulting image yields the same
// result when mounted.
package main

import (
	"bufio"
	"bytes"
	"compress/gzip"
	"flag"