ACK/Cmnt: [SRU][Jammy/Lunar/Mantic/OEM-6.5][PATCH 0/3] CVE-2023-46813

[Tim Gardner]

On 12/1/23 6:15 AM, Magali Lemes wrote:
> [Impact]
> An issue was discovered in the Linux kernel before 6.5.9, exploitable by local
> users with userspace access to MMIO registers. Incorrect access checking in the
> #VC handler and instruction emulation of the SEV-ES emulation of MMIO accesses
> could lead to arbitrary write access to kernel memory (and thus privilege
> escalation). This depends on a race condition through which userspace can
> replace an instruction before the #VC handler reads it.
> 
> [Backport]
> Clean cherry-picks.
> 
> [Test]
> Compile and boot tested.
> 
> [Regression potential]
> Limited to the users of AMD's SEV-ES feature.
> 
> Borislav Petkov (AMD) (1):
>    x86/sev: Disable MMIO emulation from user mode
> 
> Joerg Roedel (2):
>    x86/sev: Check IOBM for IOIO exceptions from user-space
>    x86/sev: Check for user-space IOIO pointing to kernel space
> 
>   arch/x86/boot/compressed/sev.c | 10 +++++++
>   arch/x86/kernel/sev-shared.c   | 53 ++++++++++++++++++++++++++++------
>   arch/x86/kernel/sev.c          | 30 +++++++++++++++++++
>   3 files changed, 84 insertions(+), 9 deletions(-)
> 
Acked-by: Tim Gardner <tim.gardner at canonical.com>

I'm not sure which will be easier to follow, e.g., 4 pull requests in 
gitea or this intertwined list of patches.

-- 
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Tim Gardner
Canonical, Inc