| 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
| ||
|
Message-ID: <20101109053440.GV5876@outflux.net> Date: Mon, 8 Nov 2010 21:34:40 -0800 From: Kees Cook <kees.cook@...onical.com> To: Dan Rosenberg <drosenberg@...curity.com> Cc: linux-kernel@...r.kernel.org, security@...nel.org Subject: Re: [PATCH] Restrict unprivileged access to kernel syslog On Mon, Nov 08, 2010 at 10:28:58PM -0500, Dan Rosenberg wrote: > The kernel syslog contains debugging information that is often useful > during exploitation of other vulnerabilities, such as kernel heap > addresses. Rather than futilely attempt to sanitize hundreds (or > thousands) of printk statements and simultaneously cripple useful > debugging functionality, it is far simpler to create an option that > prevents unprivileged users from reading the syslog. > > This patch, loosely based on grsecurity's GRKERNSEC_DMESG, creates the > dmesg_restrict sysctl. When set to "0", the default, no restrictions > are enforced. When set to "1", only users with CAP_SYS_ADMIN can read > the kernel syslog via dmesg(8) or other mechanisms. > > Signed-off-by: Dan Rosenberg <drosenberg@...curity.com> Acked-by: Kees Cook <kees.cook@...onical.com> This looks good to me -- it leaves the /proc file access alone for priv-dropping ksyslogd implementations. -Kees -- Kees Cook Ubuntu Security Team -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists