Bug 8721

Summary: AddressSanitizer: READ of size 1 in path_advance shell/ash.c:2391
Product: Busybox Reporter: Fernando Muñoz <fernando>
Component: OtherAssignee: unassigned
Status: RESOLVED FIXED    
Severity: normal CC: busybox-cvs
Priority: P5    
Version: 1.24.x   
Target Milestone: ---   
Hardware: All   
OS: Linux   
Host: Target:
Build:
Attachments: minimized test case
config used

Description Fernando Muñoz 2016-02-25 20:57:09 UTC
Created attachment 6356 [details]
minimized test case

test@kali:/root/fuzzshell$ ./busybox_unstripped sh min2.sh
=================================================================
==14108==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xb4f00256 at pc 0x08078d6a bp 0xbfffe8d8 sp 0xbfffe8cc
READ of size 1 at 0xb4f00256 thread T0
    #0 0x8078d69 in path_advance shell/ash.c:2391

0xb4f00256 is located 0 bytes to the right of 6-byte region [0xb4f00250,0xb4f00256)
allocated by thread T0 here:
    #0 0xb7afa25e in __interceptor_malloc (/usr/lib/i386-linux-gnu/libasan.so.2+0x9225e)
    #1 0x811d83f in xmalloc libbb/xfuncs_printf.c:47

SUMMARY: AddressSanitizer: heap-buffer-overflow shell/ash.c:2391 path_advance
Shadow bytes around the buggy address:
Comment 1 Fernando Muñoz 2016-02-25 20:57:41 UTC
Created attachment 6361 [details]
config used
Comment 2 Denys Vlasenko 2018-11-17 15:39:20 UTC
Fixed in git:

commit e6a63bf683f47027d36dc21b62b2f5cc3eb30a30
Author: Ron Yorston <rmy@pobox.com>
Date:   Mon Nov 12 21:10:54 2018 +0000

    ash: ensure variables are fully initialised when unset