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Fencer Vulns
high 7.3

CVE-2024-38538 json

net: bridge: xmit: make sure we have at least eth header len bytes

published 2024-06-19 2 y ago modified 2026-08-05 3 mo ago also EUVD-2024-37401

cvss
7.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

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

net: bridge: xmit: make sure we have at least eth header len bytes

syzbot triggered an uninit value[1] error in bridge device's xmit path by sending a short (less than ETH_HLEN bytes) skb. To fix it check if we can actually pull that amount instead of assuming.

Tested with dropwatch: drop at: br_dev_xmit+0xb93/0x12d0 [bridge] (0xffffffffc06739b3) origin: software timestamp: Mon May 13 11:31:53 2024 778214037 nsec protocol: 0x88a8 length: 2 original length: 2 drop reason: PKT_TOO_SMALL

[1] BUG: KMSAN: uninit-value in br_dev_xmit+0x61d/0x1cb0 net/bridge/br_device.c:65 br_dev_xmit+0x61d/0x1cb0 net/bridge/br_device.c:65 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3547 __dev_queue_xmit+0x34db/0x5350 net/core/dev.c:4341 dev_queue_xmit include/linux/netdevice.h:3091 [inline] __bpf_tx_skb net/core/filter.c:2136 [inline] __bpf_redirect_common net/core/filter.c:2180 [inline] __bpf_redirect+0x14a6/0x1620 net/core/filter.c:2187 ____bpf_clone_redirect net/core/filter.c:2460 [inline] bpf_clone_redirect+0x328/0x470 net/core/filter.c:2432 ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997 __bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2238 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] bpf_test_run+0x499/0xc30 net/bpf/test_run.c:425 bpf_prog_test_run_skb+0x14ea/0x1f20 net/bpf/test_run.c:1058 bpf_prog_test_run+0x6b7/0xad0 kernel/bpf/syscall.c:4269 __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5678 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5765 x64_sys_call+0x96b/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Patch / fix

  • Linux Linux 4.19.324, 5.4.286, 5.10.230, 5.15.172, 6.1.93, 6.6.33, 6.8.12, 6.9.3, 6.10
  • linux Debian 12 6.1.94-1
  • linux Debian 14, Debian 13 6.8.12-1

debian advisories DEBIAN-CVE-2024-38538

  • linux Ubuntu 20.04 LTS 5.4.0-202.222
  • linux Ubuntu 22.04 LTS 5.15.0-127.137
  • linux Ubuntu 24.04 LTS 6.8.0-40.40
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1136.146
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1073.79
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1013.14
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1140.149
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1072.80

ubuntu advisories UBUNTU-CVE-2024-38538

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-rt RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-kvm RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-core RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-modules RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-debug-kvm RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-debug-core RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-debug-modules RHEL 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel-rt-modules-extra RHEL 8 4.18.0-553.16.1.rt7.357.el8_10

red hat advisories RHSA-2024:5102RHSA-2024:5101RHSA-2024:5928RHSA-2024:5364RHSA-2024:5365RHSA-2024:5255

  • kernel-rt Linux Micro 6.0 6.4.0-11.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-11.1
  • kernel-livepatch-MICRO-6-0-RT_Update_3 Linux Micro 6.0 1-1.2
  • kernel-source Linux Micro 6.0 6.4.0-20.1
  • kernel-default Linux Micro 6.0 6.4.0-20.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-20.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-livepatch-MICRO-6-0_Update_3 Linux Micro 6.0 1-1.2

suse advisories SUSE-SU-2025:20077-1SUSE-SU-2025:20073-1SUSE-SU-2025:0034-1SUSE-SU-2024:4100-1SUSE-SU-2024:3617-1SUSE-SU-2024:3592-1

  • kernel AlmaLinux 9 5.14.0-427.33.1.el9_4
  • rv AlmaLinux 9 5.14.0-427.33.1.el9_4
  • perf AlmaLinux 9 5.14.0-427.33.1.el9_4
  • rtla AlmaLinux 9 5.14.0-427.33.1.el9_4
  • bpftool AlmaLinux 9 7.3.0-427.33.1.el9_4
  • libperf AlmaLinux 9 5.14.0-427.33.1.el9_4
  • kernel-rt AlmaLinux 9 5.14.0-427.33.1.el9_4
  • kernel-64k AlmaLinux 9 5.14.0-427.33.1.el9_4

almalinux advisories ALSA-2024:5928ALSA-2024:5101ALSA-2024:5102

  • kernel Rocky Linux 8 4.18.0-553.16.1.el8_10.cloud.0.1
  • kernel-rt Rocky Linux 8 4.18.0-553.16.1.rt7.357.el8_10
  • kernel Rocky Linux 8 4.18.0-553.16.1.el8_10

rocky linux advisories RXSA-2024:5101RLSA-2024:5102RLSA-2024:5101

  • kernel CBL-Mariner 2.0 5.15.176.3-1

azure linux advisories AZL-48297

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2024-38538 updated cvss 7.1

kernel: net: bridge: xmit: make sure we have at least eth header len bytes

  • 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
    affected: workaround, no fix planned “Out of support scope”
  • 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: workaround, no fix available
  • Red Hat CodeReady Linux Builder EUS (v.8.8) kernel-debuginfo-common-x86_64 4.18.0-477.67.1.el8_8, kernel-debuginfo-common-aarch64 4.18.0-477.67.1.el8_8, kernel-debuginfo-common-ppc64le 4.18.0-477.67.1.el8_8
    fixed: vendor fix RHSA-2024:5255
  • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-debuginfo-common-s390x 5.14.0-284.79.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.79.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.79.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.79.1.el9_2
    fixed: vendor fix RHSA-2024:5364
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.33.1.el9_4, perf 5.14.0-427.33.1.el9_4, rtla 5.14.0-427.33.1.el9_4, kernel-devel-matched 5.14.0-427.33.1.el9_4, kernel-64k-devel-matched 5.14.0-427.33.1.el9_4, kernel-debug-devel-matched 5.14.0-427.33.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:5928
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) perf 5.14.0-284.79.1.el9_2, rtla 5.14.0-284.79.1.el9_2, kernel-devel-matched 5.14.0-284.79.1.el9_2, kernel-64k-devel-matched 5.14.0-284.79.1.el9_2, kernel-debug-devel-matched 5.14.0-284.79.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.79.1.el9_2, +5 more
    fixed: vendor fix RHSA-2024:5364
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.16.1.el8_10, kernel 4.18.0-553.16.1.el8_10, bpftool 4.18.0-553.16.1.el8_10, kernel-core 4.18.0-553.16.1.el8_10, kernel-tools 4.18.0-553.16.1.el8_10, python3-perf 4.18.0-553.16.1.el8_10, +15 more
    fixed: vendor fix RHSA-2024:5101
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.33.1.el9_4, kernel 5.14.0-427.33.1.el9_4, kernel-64k 5.14.0-427.33.1.el9_4, kernel-core 5.14.0-427.33.1.el9_4, kernel-tools 5.14.0-427.33.1.el9_4, python3-perf 5.14.0-427.33.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:5928
show 10 more
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) perf 4.18.0-477.67.1.el8_8, kernel 4.18.0-477.67.1.el8_8, bpftool 4.18.0-477.67.1.el8_8, kernel-core 4.18.0-477.67.1.el8_8, kernel-tools 4.18.0-477.67.1.el8_8, python3-perf 4.18.0-477.67.1.el8_8, +15 more
    fixed: vendor fix RHSA-2024:5255
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool 7.0.0-284.79.1.el9_2, kernel 5.14.0-284.79.1.el9_2, kernel-64k 5.14.0-284.79.1.el9_2, kernel-core 5.14.0-284.79.1.el9_2, kernel-tools 5.14.0-284.79.1.el9_2, python3-perf 5.14.0-284.79.1.el9_2, +28 more
    fixed: vendor fix RHSA-2024:5364
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.16.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.16.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.16.1.el8_10
    fixed: vendor fix RHSA-2024:5101
  • Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.33.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.33.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.33.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.33.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.33.1.el9_4
    fixed: vendor fix RHSA-2024:5928
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-kvm 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-core 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-modules 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-debug-kvm 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-debug-core 4.18.0-553.16.1.rt7.357.el8_10, +4 more
    fixed: vendor fix RHSA-2024:5102
  • Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.33.1.el9_4, kernel-rt-kvm 5.14.0-427.33.1.el9_4, kernel-rt-core 5.14.0-427.33.1.el9_4, kernel-rt-modules 5.14.0-427.33.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.33.1.el9_4, kernel-rt-debug-core 5.14.0-427.33.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:5928
  • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-core 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-modules 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-debug-core 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-modules-core 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-debug-modules 5.14.0-284.79.1.rt14.364.el9_2, +4 more Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-kvm 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-core 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-modules 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-debug-kvm 5.14.0-284.79.1.rt14.364.el9_2, kernel-rt-debug-core 5.14.0-284.79.1.rt14.364.el9_2, +6 more
    fixed: vendor fix RHSA-2024:5365
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-core 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-modules 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-debug-core 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-debug-modules 4.18.0-553.16.1.rt7.357.el8_10, kernel-rt-modules-extra 4.18.0-553.16.1.rt7.357.el8_10, +2 more
    fixed: vendor fix RHSA-2024:5102
  • Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.33.1.el9_4, kernel-rt-core 5.14.0-427.33.1.el9_4, kernel-rt-modules 5.14.0-427.33.1.el9_4, kernel-rt-debug-core 5.14.0-427.33.1.el9_4, kernel-rt-modules-core 5.14.0-427.33.1.el9_4, kernel-rt-debug-modules 5.14.0-427.33.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:5928
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) kernel-headers 4.18.0-477.67.1.el8_8, kernel-cross-headers 4.18.0-477.67.1.el8_8
    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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
NVD 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-908 Use of Uninitialized Resource
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.