Subject: CVE-2023-52559: iommu/vt-d: Avoid memory allocation in iommu_suspend()

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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

iommu/vt-d: Avoid memory allocation in iommu_suspend()

The iommu_suspend() syscore suspend callback is invoked with IRQ disabled.
Allocating memory with the GFP_KERNEL flag may re-enable IRQs during
the suspend callback, which can cause intermittent suspend/hibernation
problems with the following kernel traces:

Calling iommu_suspend+0x0/0x1d0
------------[ cut here ]------------
WARNING: CPU: 0 PID: 15 at kernel/time/timekeeping.c:868 ktime_get+0x9b/0xb0
...
CPU: 0 PID: 15 Comm: rcu_preempt Tainted: G     U      E      6.3-intel #r1
RIP: 0010:ktime_get+0x9b/0xb0
...
Call Trace:
 <IRQ>
 tick_sched_timer+0x22/0x90
 ? __pfx_tick_sched_timer+0x10/0x10
 __hrtimer_run_queues+0x111/0x2b0
 hrtimer_interrupt+0xfa/0x230
 __sysvec_apic_timer_interrupt+0x63/0x140
 sysvec_apic_timer_interrupt+0x7b/0xa0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1f/0x30
...
------------[ cut here ]------------
Interrupts enabled after iommu_suspend+0x0/0x1d0
WARNING: CPU: 0 PID: 27420 at drivers/base/syscore.c:68 syscore_suspend+0x147/0x270
CPU: 0 PID: 27420 Comm: rtcwake Tainted: G     U  W   E      6.3-intel #r1
RIP: 0010:syscore_suspend+0x147/0x270
...
Call Trace:
 <TASK>
 hibernation_snapshot+0x25b/0x670
 hibernate+0xcd/0x390
 state_store+0xcf/0xe0
 kobj_attr_store+0x13/0x30
 sysfs_kf_write+0x3f/0x50
 kernfs_fop_write_iter+0x128/0x200
 vfs_write+0x1fd/0x3c0
 ksys_write+0x6f/0xf0
 __x64_sys_write+0x1d/0x30
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

Given that only 4 words memory is needed, avoid the memory allocation in
iommu_suspend().

The Linux kernel CVE team has assigned CVE-2023-52559 to this issue.

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

	Issue introduced in 5.11 with commit 33e07157105e and fixed in 5.15.136 with commit 29298c85a81a
	Issue introduced in 5.11 with commit 33e07157105e and fixed in 6.1.57 with commit c12ef025add7
	Issue introduced in 5.11 with commit 33e07157105e and fixed in 6.5.7 with commit 496c591f0b38
	Issue introduced in 5.11 with commit 33e07157105e and fixed in 6.6 with commit 59df44bfb0ca

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-2023-52559
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/iommu/intel/iommu.c
	drivers/iommu/intel/iommu.h

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/29298c85a81abdc512e87537515ed4b1a9601d0e
	https://git.kernel.org/stable/c/c12ef025add77ca3a0902e8719d552b6d47b4282
	https://git.kernel.org/stable/c/496c591f0b389eb782f36d9d4c2564b9a865eed0
	https://git.kernel.org/stable/c/59df44bfb0ca4c3ee1f1c3c5d0ee8e314844799e