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Fencer Vulns
high 7.8

CVE-2022-49814 json

kcm: close race conditions on sk_receive_queue

published 2025-05-01 18 mo ago modified 2026-08-05 3 mo ago also EUVD-2025-12951

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

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

kcm: close race conditions on sk_receive_queue

sk->sk_receive_queue is protected by skb queue lock, but for KCM sockets its RX path takes mux->rx_lock to protect more than just skb queue. However, kcm_recvmsg() still only grabs the skb queue lock, so race conditions still exist.

We can teach kcm_recvmsg() to grab mux->rx_lock too but this would introduce a potential performance regression as struct kcm_mux can be shared by multiple KCM sockets.

So we have to enforce skb queue lock in requeue_rx_msgs() and handle skb peek case carefully in kcm_wait_data(). Fortunately, skb_recv_datagram() already handles it nicely and is widely used by other sockets, we can just switch to skb_recv_datagram() after getting rid of the unnecessary sock lock in kcm_recvmsg() and kcm_splice_read(). Side note: SOCK_DONE is not used by KCM sockets, so it is safe to get rid of this check too.

I ran the original syzbot reproducer for 30 min without seeing any issue.

Patch / fix

  • Linux Linux 4.14.300, 4.19.267, 5.4.225, 5.10.156, 5.15.80, 6.0.10, 6.1
  • linux Debian 14, Debian 13, Debian 12 6.0.10-1

debian advisories DEBIAN-CVE-2022-49814

  • linux Ubuntu 18.04 LTS 4.15.0-206.217
  • linux Ubuntu 20.04 LTS 5.4.0-144.161
  • linux Ubuntu 22.04 LTS 5.15.0-67.74
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1151.164
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1097.105
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1031.35
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1101.110
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1030.37

ubuntu advisories UBUNTU-CVE-2022-49814

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-syms SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 4.12.14-122.266.1
  • kernel-source SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 4.12.14-122.266.1
  • kernel-default SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS, SLE Live Patching 12 SP5 4.12.14-122.266.1
  • kgraft-patch-SLE12-SP5_Update_70 SLE Live Patching 12 SP5 1-8.5.1

suse advisories SUSE-SU-2025:02334-1

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-2022-49814 updated

kernel: kcm: close race conditions on sk_receive_queue

  • 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 9 rv, perf, rtla, kernel, bpftool, libperf, +83 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

0.17% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
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.