linux-kernel - Re: [PATCH v3 0/2] binfmt_elf, coredump: Log the reason of the failed core dumps

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <fa6a6ba2-c920-477c-8145-a437f18a79a0@linux.microsoft.com>
Date: Mon, 22 Jul 2024 12:33:38 -0700
From: Roman Kisel <romank@...ux.microsoft.com>
To: Kees Cook <kees@...nel.org>
Cc: akpm@...ux-foundation.org, apais@...ux.microsoft.com, ardb@...nel.org,
 bigeasy@...utronix.de, brauner@...nel.org, ebiederm@...ssion.com,
 jack@...e.cz, linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-mm@...ck.org, nagvijay@...rosoft.com, oleg@...hat.com,
 tandersen@...flix.com, vincent.whitchurch@...s.com, viro@...iv.linux.org.uk,
 apais@...rosoft.com, benhill@...rosoft.com, ssengar@...rosoft.com,
 sunilmut@...rosoft.com, vdso@...bites.dev
Subject: Re: [PATCH v3 0/2] binfmt_elf, coredump: Log the reason of the failed
 core dumps



On 7/19/2024 10:26 AM, Kees Cook wrote:
> On Thu, Jul 18, 2024 at 11:27:23AM -0700, Roman Kisel wrote:
>> A powerful way to diagnose crashes is to analyze the core dump produced upon
>> the failure. Missing or malformed core dump files hinder these investigations.
>> I'd like to propose changes that add logging as to why the kernel would not
>> finish writing out the core dump file.
>>
>> To help in diagnosing the user mode helper not writing out the entire coredump
>> contents, the changes also log short statistics on the dump collection. I'd
>> advocate for keeping this at the info level on these grounds.
>>
>> For validation, I built the kernel and a simple user space to exercize the new
>> code.
>>
>> [V3]
>>    - Standartized the existing logging to report TGID and comm consistently
>>    - Fixed compiler warnings for the 32-bit systems (used %zd in the format strings)
>>
>> [V2]
>>    https://lore.kernel.org/all/20240712215223.605363-1-romank@linux.microsoft.com/
>>    - Used _ratelimited to avoid spamming the system log
>>    - Added comm and PID to the log messages
>>    - Added logging to the failure paths in dump_interrupted, dump_skip, and dump_emit
>>    - Fixed compiler warnings produced when CONFIG_COREDUMP is disabled
>>
>> [V1]
>>    https://lore.kernel.org/all/20240617234133.1167523-1-romank@linux.microsoft.com/
>>
>> Roman Kisel (2):
>>    coredump: Standartize and fix logging
>>    binfmt_elf, coredump: Log the reason of the failed core dumps
>>
>>   fs/binfmt_elf.c          |  48 +++++++++----
>>   fs/coredump.c            | 150 +++++++++++++++++++++++++++------------
>>   include/linux/coredump.h |  30 +++++++-
>>   kernel/signal.c          |  21 +++++-
>>   4 files changed, 188 insertions(+), 61 deletions(-)
> 
> This looks good to me! I'll put this in -next once the merge window
> closes. Thanks!
> 
Kees, thank you for your guidance!

> -Kees
> 

-- 
Thank you,
Roman