cbcvebase.
CVE-2024-26976
published 2024-05-01

CVE-2024-26976: In the Linux kernel, the following vulnerability has been resolved: KVM: Always flush async #PF workqueue when vCPU is being destroyed Always flush the…

PriorityP431high7CVSS 3.1
AVLACHPRLUINSUCHIHAH
EPSS
0.26%
17.5th percentile
In the Linux kernel, the following vulnerability has been resolved: KVM: Always flush async #PF workqueue when vCPU is being destroyed Always flush the per-vCPU async #PF workqueue when a vCPU is clearing its completion queue, e.g. when a VM and all its vCPUs is being destroyed. KVM must ensure that none of its workqueue callbacks is running when the last reference to the KVM _module_ is put. Gifting a reference to the associated VM prevents the workqueue callback from dereferencing freed vCPU/VM memory, but does not prevent the KVM module from being unloaded before the callback completes. Drop the misguided VM refcount gifting, as calling kvm_put_kvm() from async_pf_execute() if kvm_put_kvm() flushes the async #PF workqueue will result in deadlock. async_pf_execute() can't return until kvm_put_kvm() finishes, and kvm_put_kvm() can't return until async_pf_execute() finishes: WARNING: CPU: 8 PID: 251 at virt/kvm/kvm_main.c:1435 kvm_put_kvm+0x2d/0x320 [kvm] Modules linked in: vhost_net vhost vhost_iotlb tap kvm_intel kvm irqbypass CPU: 8 PID: 251 Comm: kworker/8:1 Tainted: G W 6.6.0-rc1-e7af8d17224a-x86/gmem-vm #119 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Workqueue: events async_pf_execute [kvm] RIP: 0010:kvm_put_kvm+0x2d/0x320 [kvm] Call Trace: async_pf_execute+0x198/0x260 [kvm] process_one_work+0x145/0x2d0 worker_thread+0x27e/0x3a0 kthread+0xba/0xe0 ret_from_fork+0x2d/0x50 ret_from_fork_asm+0x11/0x20 ---[ end trace 0000000000000000 ]--- INFO: task kworker/8:1:251 blocked for more than 120 seconds. Tainted: G W 6.6.0-rc1-e7af8d17224a-x86/gmem-vm #119 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/8:1 state:D stack:0 pid:251 ppid:2 flags:0x00004000 Workqueue: events async_pf_execute [kvm] Call Trace: __schedule+0x33f/0xa40 schedule+0x53/0xc0 schedule_timeout+0x12a/0x140 __wait_for_common+0x8d/0x1d0 __flush_work.isra.0+0x19f/0x2c0 kvm_clear_async_pf_completion_queue+0x129/0x190 [kvm] kvm_a

Affected

27 ranges· showing 25
VendorProductVersion rangeFixed in
debiandebian_linux
debianlinux< linux 6.1.85-1 (bookworm)linux 6.1.85-1 (bookworm)
linuxlinux
linuxlinux>= af585b921e5d1e919947c4b1164b59507fe7cd7b < ab2c2f5d9576112ad22cfd3798071cb74693b1f5ab2c2f5d9576112ad22cfd3798071cb74693b1f5
linuxlinux>= af585b921e5d1e919947c4b1164b59507fe7cd7b < 82e25cc1c2e93c3023da98be282322fc08b61ffb82e25cc1c2e93c3023da98be282322fc08b61ffb
linuxlinux>= af585b921e5d1e919947c4b1164b59507fe7cd7b < f8730d6335e5f43d09151fca1f0f41922209a264f8730d6335e5f43d09151fca1f0f41922209a264
linuxlinux>= af585b921e5d1e919947c4b1164b59507fe7cd7b < 83d3c5e309611ef593e2fcb78444fc8ceedf9bac83d3c5e309611ef593e2fcb78444fc8ceedf9bac
linuxlinux>= af585b921e5d1e919947c4b1164b59507fe7cd7b < b54478d20375874aeee257744dedfd3e413432ffb54478d20375874aeee257744dedfd3e413432ff
linuxlinux>= af585b921e5d1e919947c4b1164b59507fe7cd7b < a75afe480d4349c524d9c659b1a5a544dbc39a98a75afe480d4349c524d9c659b1a5a544dbc39a98
linuxlinux>= af585b921e5d1e919947c4b1164b59507fe7cd7b < 4f3a3bce428fb439c66a578adc447afce7b4a7504f3a3bce428fb439c66a578adc447afce7b4a750
linuxlinux>= af585b921e5d1e919947c4b1164b59507fe7cd7b < caa9af2e27c275e089d702cfbaaece3b42bca31bcaa9af2e27c275e089d702cfbaaece3b42bca31b
linuxlinux>= af585b921e5d1e919947c4b1164b59507fe7cd7b < 3d75b8aa5c29058a512db29da7cbee80527241573d75b8aa5c29058a512db29da7cbee8052724157
linuxlinux_kernel>= 0 < 5.10.216-15.10.216-1
linuxlinux_kernel>= 0 < 6.1.85-16.1.85-1
linuxlinux_kernel>= 0 < 6.7.12-16.7.12-1
linuxlinux_kernel>= 0 < 6.7.12-16.7.12-1
linuxlinux_kernel>= 0 < 5.4.0-189.2095.4.0-189.209
linuxlinux_kernel>= 0 < 5.15.0-116.1265.15.0-116.126
linuxlinux_kernel>= 0 < 6.8.0-35.356.8.0-35.35
linuxlinux_kernel>= 2.6.38 < 4.19.3124.19.312
linuxlinux_kernel>= 4.20 < 5.4.2745.4.274
linuxlinux_kernel>= 5.11 < 5.15.1545.15.154
linuxlinux_kernel>= 5.16 < 6.1.846.1.84
linuxlinux_kernel>= 5.5 < 5.10.2155.10.215
linuxlinux_kernel>= 6.2 < 6.6.246.6.24

CVSS provenance

nvdv3.17.0HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.0HIGH
vendor_debian7.0HIGH
vendor_redhat7.0HIGH
vendor_ubuntu7.0HIGH
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