linux (5.10.46-4) unstable; urgency=medium * From Linux 5.10.46-4, unprivileged calls to bpf() are disabled by default, mitigating several security issues. However, an admin can still change this setting later on, if needed, by writing 0 or 1 to the kernel.unprivileged_bpf_disabled sysctl. If you prefer to keep unprivileged calls to bpf() enabled, set the sysctl: kernel.unprivileged_bpf_disabled = 0 which is the upstream default. -- Salvatore Bonaccorso Mon, 02 Aug 2021 22:59:24 +0200 linux (5.10~rc7-1~exp2) unstable; urgency=medium * From Linux 5.10, all users are allowed to create user namespaces by default. This will allow programs such as web browsers and container managers to create more restricted sandboxes for untrusted or less-trusted code, without the need to run as root or to use a setuid-root helper. The previous Debian default was to restrict this feature to processes running as root, because it exposed more security issues in the kernel. However, the security benefits of more widespread sandboxing probably now outweigh this risk. If you prefer to keep this feature restricted, set the sysctl: kernel.unprivileged_userns_clone = 0 -- Ben Hutchings Sun, 13 Dec 2020 17:11:36 +0100 linux-latest (86) unstable; urgency=medium * From Linux 4.13.10-1, AppArmor is enabled by default. This allows defining a "profile" for each installed program that can mitigate security vulnerabilities in it. However, an incorrect profile might disable some functionality of the program. In case you suspect that an AppArmor profile is incorrect, see and consider reporting a bug in the package providing the profile. The profile may be part of the program's package or apparmor-profiles. -- Ben Hutchings Thu, 30 Nov 2017 20:08:25 +0000 linux-latest (81) unstable; urgency=medium * From Linux 4.10, the old 'virtual syscall' interface on 64-bit PCs (amd64) is disabled. This breaks chroot environments and containers that use (e)glibc 2.13 and earlier, including those based on Debian 7 or RHEL/CentOS 6. To re-enable it, set the kernel parameter: vsyscall=emulate -- Ben Hutchings Fri, 30 Jun 2017 23:50:03 +0100 linux-latest (76) unstable; urgency=medium * From Linux 4.8, several changes have been made in the kernel configuration to 'harden' the system, i.e. to mitigate security bugs. Some changes may cause legitimate applications to fail, and can be reverted by run-time configuration: - On most architectures, the /dev/mem device can no longer be used to access devices that also have a kernel driver. This breaks dosemu and some old user-space graphics drivers. To allow this, set the kernel parameter: iomem=relaxed - The kernel log is no longer readable by unprivileged users. To allow this, set the sysctl: kernel.dmesg_restrict=0 -- Ben Hutchings Sat, 29 Oct 2016 02:05:32 +0100 linux-latest (75) unstable; urgency=medium * From Linux 4.7, the iptables connection tracking system will no longer automatically load helper modules. If your firewall configuration depends on connection tracking helpers, you should explicitly load the required modules. For more information, see . -- Ben Hutchings Sat, 29 Oct 2016 01:53:18 +0100