Skip to content
Fencer Vulns
no cvss —

CVE-2022-50738 json

vhost-vdpa: fix an iotlb memory leak

published 2025-12-24 10 mo ago modified 2026-06-17 4 mo ago also EUVD-2022-55823

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

Summary

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

vhost-vdpa: fix an iotlb memory leak

Before commit 3d5698793897 ("vhost-vdpa: introduce asid based IOTLB") we called vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1) during release to free all the resources allocated when processing user IOTLB messages through vhost_vdpa_process_iotlb_update(). That commit changed the handling of IOTLB a bit, and we accidentally removed some code called during the release.

We partially fixed this with commit 037d4305569a ("vhost-vdpa: call vhost_vdpa_cleanup during the release") but a potential memory leak is still there as showed by kmemleak if the application does not send VHOST_IOTLB_INVALIDATE or crashes:

unreferenced object 0xffff888007fbaa30 (size 16): comm "blkio-bench", pid 914, jiffies 4294993521 (age 885.500s) hex dump (first 16 bytes): 40 73 41 07 80 88 ff ff 00 00 00 00 00 00 00 00 @sA............. backtrace: [<0000000087736d2a>] kmem_cache_alloc_trace+0x142/0x1c0 [<0000000060740f50>] vhost_vdpa_process_iotlb_msg+0x68c/0x901 [vhost_vdpa] [<0000000083e8e205>] vhost_chr_write_iter+0xc0/0x4a0 [vhost] [<000000008f2f414a>] vhost_vdpa_chr_write_iter+0x18/0x20 [vhost_vdpa] [<00000000de1cd4a0>] vfs_write+0x216/0x4b0 [<00000000a2850200>] ksys_write+0x71/0xf0 [<00000000de8e720b>] __x64_sys_write+0x19/0x20 [<0000000018b12cbb>] do_syscall_64+0x3f/0x90 [<00000000986ec465>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Let's fix this calling vhost_vdpa_iotlb_unmap() on the whole range in vhost_vdpa_remove_as(). We move that call before vhost_dev_cleanup() since we need a valid v->vdev.mm in vhost_vdpa_pa_unmap(). vhost_iotlb_reset() call can be removed, since vhost_vdpa_iotlb_unmap() on the whole range removes all the entries.

The kmemleak log reported was observed with a vDPA device that has `use_va` set to true (e.g. VDUSE). This patch has been tested with both types of devices.

Patch / fix

  • Linux Linux 6.0.19, 6.1.5, 6.2
  • linux Debian 14, Debian 13, Debian 12 6.1.7-1

debian advisories DEBIAN-CVE-2022-50738

  • kernel RHEL 9 5.14.0-284.11.1.el9_2
  • perf RHEL 9 5.14.0-284.11.1.el9_2
  • rtla RHEL 9 5.14.0-284.11.1.el9_2
  • bpftool RHEL 9 7.0.0-284.11.1.el9_2
  • kernel-64k RHEL 9 5.14.0-284.11.1.el9_2
  • kernel-core RHEL 9 5.14.0-284.11.1.el9_2
  • kernel-tools RHEL 9 5.14.0-284.11.1.el9_2
  • python3-perf RHEL 9 5.14.0-284.11.1.el9_2

red hat advisories RHSA-2023:2458

  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.133.1
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.133.1
  • kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.133.1
  • kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.133.1
  • kernel-obs-build SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.133.1
  • kernel-default-base SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.133.1.150500.6.65.1
  • kernel-rt SLE Micro 5.5 5.14.21-150500.13.118.1
  • kernel-source-rt SLE Micro 5.5 5.14.21-150500.13.118.1

suse advisories SUSE-SU-2026:0317-1SUSE-SU-2026:0263-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-50738 updated cvss 5.5

kernel: Linux kernel: vhost-vdpa memory leak leading to Denial of Service

  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux AppStream (v. 9) perf 5.14.0-284.11.1.el9_2, rtla 5.14.0-284.11.1.el9_2, kernel-devel-matched 5.14.0-284.11.1.el9_2, kernel-64k-devel-matched 5.14.0-284.11.1.el9_2, kernel-debug-devel-matched 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.11.1.el9_2, +5 more Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.0.0-284.11.1.el9_2, kernel 5.14.0-284.11.1.el9_2, kernel-64k 5.14.0-284.11.1.el9_2, kernel-core 5.14.0-284.11.1.el9_2, kernel-tools 5.14.0-284.11.1.el9_2, python3-perf 5.14.0-284.11.1.el9_2, +28 more Red Hat Enterprise Linux CRB (v. 9) kernel-debuginfo-common-s390x 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.11.1.el9_2
    fixed: vendor fix RHSA-2023:2458
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.