linux-kernel - [PATCH 0/2] sysctl: cap file-max value at ULONG

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-next>] [day] [month] [year] [list]

Date:   Sun, 14 Oct 2018 15:25:08 +0200
From:   Christian Brauner <christian@...uner.io>
To:     keescook@...omium.org, linux-kernel@...r.kernel.org
Cc:     ebiederm@...ssion.com, mcgrof@...nel.org,
        akpm@...ux-foundation.org, joe.lawrence@...hat.com,
        longman@...hat.com, Christian Brauner <christian@...uner.io>
Subject: [PATCH 0/2] sysctl: cap file-max value at ULONG_MAX

Hey,

Currently, when writing

echo 18446744073709551616 > /proc/sys/fs/file-max

/proc/sys/fs/file-max will overflow and be set to 0. That quickly
crashes the system. Let's detect the overflow and set to ULONG_MAX in
this case effectively capping the value.

The patch tries to ensure that there is no other user visible change in
behavior for other values. Only when a maximum value is set for a
specific sysctl will it be capped on overflow. The details are outlined
in the commit message of the first commit.

(This patchset is in reference to https://lkml.org/lkml/2018/10/11/585.)

Thanks!
Christian

Christian Brauner (2):
  sysctl: add overflow detection to proc_get_long()
  sysctl: handle overflow for file-max

 kernel/sysctl.c | 54 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 12 deletions(-)

-- 
2.17.1