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

[zhengzucheng <zhengzucheng@huawei.com>]

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@amd.com>
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@amd.com>
     Suggested-by: Christian König <christian.koenig@amd.com>
     Reviewed-by: Christian König <christian.koenig@amd.com>
     Signed-off-by: Alex Deucher <alexander.deucher@amd.com>


> 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@gmail.com>
>>
>> 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