[SRU][F][PATCH 0/1] CVE-2024-56662

[Massimiliano Pellizzer]

https://ubuntu.com/security/CVE-2024-56662

[ Impact ]

acpi: nfit: vmalloc-out-of-bounds Read in acpi_nfit_ctl

Fix an issue detected by syzbot with KASAN:

BUG: KASAN: vmalloc-out-of-bounds in cmd_to_func drivers/acpi/nfit/
core.c:416 [inline]
BUG: KASAN: vmalloc-out-of-bounds in acpi_nfit_ctl+0x20e8/0x24a0
drivers/acpi/nfit/core.c:459

The issue occurs in cmd_to_func when the call_pkg->nd_reserved2
array is accessed without verifying that call_pkg points to a buffer
that is appropriately sized as a struct nd_cmd_pkg. This can lead
to out-of-bounds access and undefined behavior if the buffer does not
have sufficient space.

To address this, a check was added in acpi_nfit_ctl() to ensure that
buf is not NULL and that buf_len is less than sizeof(*call_pkg)
before accessing it. This ensures safe access to the members of
call_pkg, including the nd_reserved2 array.

[ Fix ]

Plucky: Not affected
Oracular: Fixed via upstream stable updates (LP: #2097332)
Noble: Fixed via upstream stable updates (LP: #2102181)
Jammy: Fixed via upstream stable updates (LP: #2095302)
Focal: Backported from mainline

[ Test Plan ]

Compile tested only.

[ Where Problems Could Occur ]

A regression here is unlikely due to the very limited scope
of the patch.