title: iommu/vt-d: Avoid memory allocation in iommu_suspend()
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().
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 33e07157105e, lessThan: 29298c85a81a, status: affected, versionType: git
version: 33e07157105e, lessThan: c12ef025add7, status: affected, versionType: git
version: 33e07157105e, lessThan: 496c591f0b38, status: affected, versionType: git
version: 33e07157105e, lessThan: 59df44bfb0ca, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 5.11, status: affected
version: 0, lessThan: 5.11, status: unaffected, versionType: custom
version: 5.15.136, lessThanOrEqual: 5.15.*, status: unaffected, versionType: custom
version: 6.1.57, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.5.7, lessThanOrEqual: 6.5.*, status: unaffected, versionType: custom
version: 6.6, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
