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kernel/kernel-std/debian/deb_patches/series
Haiqing Bai 20e578cdd8 kernel: Disable unprivileged eBPF by default
The following warning message is printed out starting with kernel
version 5.10.105 in response to a newer Spectre-type security issue:

  Spectre V2: WARNING: Unprivileged eBPF is enabled with eIBRS on, data
  leaks possible via Spectre v2 BHB attacks!

This message is printed out when Spectre v2 mitigations are enabled and
unprivileged eBPF is enabled.

This warning message was introduced with commit afc2d635b5e1
("x86/speculation: Include unprivileged eBPF status in spectre v2
mitigation reporting") in the Linux stable team's linux-5.10.y branch.
The first tag that includes this change in that branch is "v5.10.105".

This commit sets the "CONFIG_BPF_UNPRIV_DEFAULT_OFF" Kconfig option to
suppress the aforementioned warning message. Note that unprivileged eBPF
is disabled by default in most distributions. Disabling unprivileged
eBPF is recommended as a (partial) mitigation against attack primitives
known as Spectre-v2-BHB ("Spectre v2 aided by the Branch History
Buffer"), as documented at the following links:
- https://www.vusec.net/projects/bhi-spectre-bhb/
- https://www.intel.com/content/www/us/en/developer/articles/\
  technical/software-security-guidance/technical-documentation/\
  branch-history-injection.html

Also note that if unprivileged eBPF is re-enabled at runtime via
"sysctl" or by writing to "/proc/sys/kernel/unprivileged_bpf_disabled",
then the warning message in question will appear in the kernel logs.

Verification:
- On a test system, remove the kernel command line argument
  'nospectre_v2' from "/boot/efi/EFI/BOOT/boot.env", and save the file.
- Reboot.
- With this commit, the following warning message does not appear in the
  kernel's logs, as confirmed with "dmesg | grep eIBRS": "Spectre V2:
  WARNING: Unprivileged eBPF is enabled with eIBRS on, data leaks
  possible via Spectre v2 BHB attacks!". (Without this commit, the
  aforementioned warning message would appear in the kernel logs.)

Closes-Bug: 2019268

Signed-off-by: Haiqing Bai <haiqing.bai@windriver.com>
Change-Id: I03d9ef494384c52cd4d81d02d8c76cd0fef6edb5
2023-05-16 12:46:33 +00:00

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0001-kernel-std-Remove-the-old-changelog-file.patch
0002-kernel-std-Add-a-new-changelog-file-for-linux-yocto-.patch
0003-kernel-std-Add-a-kernel-config-file-for-stx-debian.patch
0004-kernel-std-Adapt-the-debian-folder-for-new-source.patch
0005-kernel-modules-sign-kernel-modules.patch
0006-Debian-align-config-file-with-stx-centos.patch
0007-Debian-update-5.10-Kernel-to-5.10.99.patch
0008-config-set-configs-needed-for-secure-boot.patch
0009-Drop-Android-patches.patch
0010-Debian-Disable-CONFIG_BNXT.patch
0011-Debian-Hardcode-net.naming-scheme-in-CONFIG_CMDLINE.patch
0012-Debian-update-5.10-Kernel-to-5.10.112.patch
0013-kernel-std-fix-proc-version-content.patch
0014-kernel-std-clean-patches-from-debian-release.patch
0015-Debian-Added-apparmor-security-module.patch
0016-debian-rules.real-Parallelize-xz-compression.patch
0017-Debian-Enable-WireGuard-config.patch
0018-Place-module-signing-keys-in-a-separate-packa.patch
0019-Upgrade-5.10-kernel-to-5.10.152.patch
0020-kernel-std-unset-LOCK_DOWN_IN_EFI_SECURE_BOOT.patch
0021-config-don-t-unset-CONFIG_EFIVAR_FS.patch
0022-Upgrade-5.10-kernel-to-5.10.162.patch
0023-Fix-badly-formatted-trailer-line.patch
0024-Upgrade-5.10-kernel-to-5.10.177.patch
0025-Disable-unprivileged-eBPF-by-default.patch