URL:
<http://savannah.gnu.org/bugs/?51153>
Summary: SYSLINUX config parsing is very fragile
Project: GNU GRUB
Submitted by: felix_s
Submitted on: Thu 01 Jun 2017 10:00:20 AM UTC
Category: None
Severity: Major
Priority: 5 - Normal
Item Group: Software Error
Status: None
Privacy: Public
Assigned to: None
Originator Name:
Originator Email:
Open/Closed: Open
Discussion Lock: Any
Release:
Release: Git master
Reproducibility: Every Time
Planned Release: None
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Details:
Attached are two config files. One of them produces a crash (null pointer
dereference) when fed to grub-syslinux2cfg or GRUB's syslinux_configfile
command; the other produces an unhelpful 'kernel without label' message,
without even so much as a line number. Both are understood by vanilla SYSLINUX
normally; they are variously processed versons of SYSLINUX config file from
SystemRescueCd.
The former bug is because the command-line arguments to ifcpu64.c32 are
misparsed (GRUB's parser doesn't understand command-line arguments for kernel
alternatives); the latter is because cmd_menudefault doesn't understand a
label specifier in a MENU DEFAULT statement.
The SYSLINUX config parsing code generally seems quite fragile. From a very
cursory inspection, I've noticed a potential memory leak when encountering
multiple DEFAULT statements (cmd_default). A more thorough audit may reveal
more such issues.
_______________________________________________________
File Attachments:
-------------------------------------------------------
Date: Thu 01 Jun 2017 10:00:20 AM UTC Name: crash.syslinux.cfg Size: 6kB
By: felix_s
<http://savannah.gnu.org/bugs/download.php?file_id=40831>
-------------------------------------------------------
Date: Thu 01 Jun 2017 10:00:20 AM UTC Name: syslinux.cfg Size: 20kB By:
felix_s
<http://savannah.gnu.org/bugs/download.php?file_id=40832>
_______________________________________________________
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