Re: CVE-2024-26650: platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe

From: zhengzucheng
Date: Thu May 23 2024 - 04:50:56 EST



在 2024/5/22 3:31, Michal Hocko 写道:
This patch has been reverted in upstream by 03c6284df179 ("Revert
"drm/amd/amdgpu: Fix potential ioremap() memory leaks in
amdgpu_device_init()"") and based on the changelog the CVE should be
rejected.

hi Michal Hocko

This reverted patch was previously used to resolve CVE-2024-35928 ?

so CVE-2024-35928 should be rejected?


commit 03c6284df179de3a4a6e0684764b1c71d2a405e2
Author: Ma Jun <Jun.Ma2@xxxxxxx>
Date:   Tue Mar 19 15:24:03 2024 +0800

    Revert "drm/amd/amdgpu: Fix potential ioremap() memory leaks in amdgpu_device_init()"

    This patch causes the following iounmap erorr and calltrace
    iounmap: bad address 00000000d0b3631f

    The original patch was unjustified because amdgpu_device_fini_sw() will
    always cleanup the rmmio mapping.

    This reverts commit eb4f139888f636614dab3bcce97ff61cefc4b3a7.

    Signed-off-by: Ma Jun <Jun.Ma2@xxxxxxx>
    Suggested-by: Christian König <christian.koenig@xxxxxxx>
    Reviewed-by: Christian König <christian.koenig@xxxxxxx>
    Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>


On Tue 26-03-24 17:50:16, Lee Jones wrote:
Description
===========

In the Linux kernel, the following vulnerability has been resolved:

platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe

p2sb_bar() unhides P2SB device to get resources from the device. It
guards the operation by locking pci_rescan_remove_lock so that parallel
rescans do not find the P2SB device. However, this lock causes deadlock
when PCI bus rescan is triggered by /sys/bus/pci/rescan. The rescan
locks pci_rescan_remove_lock and probes PCI devices. When PCI devices
call p2sb_bar() during probe, it locks pci_rescan_remove_lock again.
Hence the deadlock.

To avoid the deadlock, do not lock pci_rescan_remove_lock in p2sb_bar().
Instead, do the lock at fs_initcall. Introduce p2sb_cache_resources()
for fs_initcall which gets and caches the P2SB resources. At p2sb_bar(),
refer the cache and return to the caller.

Before operating the device at P2SB DEVFN for resource cache, check
that its device class is PCI_CLASS_MEMORY_OTHER 0x0580 that PCH
specifications define. This avoids unexpected operation to other devices
at the same DEVFN.

Tested-by Klara Modin <klarasmodin@xxxxxxxxx>

The Linux kernel CVE team has assigned CVE-2024-26650 to this issue.


Affected and fixed versions
===========================

Issue introduced in 6.0 with commit 9745fb07474f and fixed in 6.1.76 with commit 2841631a0365
Issue introduced in 6.0 with commit 9745fb07474f and fixed in 6.6.15 with commit 847e1eb30e26
Issue introduced in 6.0 with commit 9745fb07474f and fixed in 6.7.3 with commit d281ac9a987c
Issue introduced in 6.0 with commit 9745fb07474f and fixed in 6.8 with commit 5913320eb0b3

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions. The official CVE entry at
https://cve.org/CVERecord/?id=CVE-2024-26650
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
drivers/platform/x86/p2sb.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes. Individual
changes are never tested alone, but rather are part of a larger kernel
release. Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all. If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
https://git.kernel.org/stable/c/2841631a03652f32b595c563695d0461072e0de4
https://git.kernel.org/stable/c/847e1eb30e269a094da046c08273abe3f3361cf2
https://git.kernel.org/stable/c/d281ac9a987c553d93211b90fd4fe97d8eca32cd
https://git.kernel.org/stable/c/5913320eb0b3ec88158cfcb0fa5e996bf4ef681b