ACK: [SRU][X][PATCH 1/1] UBUNTU: SAUCE: Revert "printk: hash addresses printed with %p"

[Krzysztof Kozlowski]

On 01/04/2021 11:13, Kleber Sacilotto de Souza wrote:
> BugLink: https://bugs.launchpad.net/bugs/1922200
> 
> This reverts commit 5d742149ceb112c61ee576f371b574da32532c43 (commit
> ad67b74d2469d9b82aaa572d76474c95bc484d57 upstream).
> 
> The backport of this upstream commit, applied to fix CVEs
> CVE-2018-5953/CVE-2018-5995/CVE-2018-7754 on xenial/linux, introduced a
> regression on the addresses exported via /proc interfaces (mainly
> /proc/kallsyms). The patch leaks what the address 0x0 hashes to for
> regular users instead of the expected zeroed out values. It also mangles
> the default address for 'startup_64' expected to be 'ffffffff81000000'
> for non-kaslr kernels (<4.15).
> 
> Signed-off-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>
> ---
>  Documentation/printk-formats.txt |  11 ----
>  lib/test_printf.c                | 108 +++++++++++--------------------
>  lib/vsprintf.c                   |  81 ++---------------------
>  3 files changed, 45 insertions(+), 155 deletions(-)


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski at canonical.com>

The backport changes user-visible behavior (e.g. logs) so the interface
used by some apps might be affected. The impact of CVE is low, so I
agree with skipping the backport.

Best regards,
Krzysztof