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Fencer Vulns
high 7.8

CVE-2024-36979 json

net: bridge: mst: fix vlan use-after-free

published 2024-06-19 2 y ago modified 2026-08-05 3 mo ago also EUVD-2024-36329

cvss
7.8
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 17%
public exploits
0
none known

Summary

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

net: bridge: mst: fix vlan use-after-free

syzbot reported a suspicious rcu usage[1] in bridge's mst code. While fixing it I noticed that nothing prevents a vlan to be freed while walking the list from the same path (br forward delay timer). Fix the rcu usage and also make sure we are not accessing freed memory by making br_mst_vlan_set_state use rcu read lock.

[1] WARNING: suspicious RCU usage 6.9.0-rc6-syzkaller #0 Not tainted ----------------------------- net/bridge/br_private.h:1599 suspicious rcu_dereference_protected() usage! ... stack backtrace: CPU: 1 PID: 8017 Comm: syz-executor.1 Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712 nbp_vlan_group net/bridge/br_private.h:1599 [inline] br_mst_set_state+0x1ea/0x650 net/bridge/br_mst.c:105 br_set_state+0x28a/0x7b0 net/bridge/br_stp.c:47 br_forward_delay_timer_expired+0x176/0x440 net/bridge/br_stp_timer.c:88 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1793 expire_timers kernel/time/timer.c:1844 [inline] __run_timers kernel/time/timer.c:2418 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2429 run_timer_base kernel/time/timer.c:2438 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2448 __do_softirq+0x2c6/0x980 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 ba d1 84 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90013657100 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920026cae2c RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaca00 RDI: ffffffff8c1eaa60 RBP: ffffc90013657260 R08: ffffffff92efe507 R09: 1ffffffff25dfca0 R10: dffffc0000000000 R11: fffffbfff25dfca1 R12: 1ffff920026cae28 R13: dffffc0000000000 R14: ffffc90013657160 R15: 0000000000000246

Patch / fix

  • Linux Linux 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-2024-36979

  • linux Ubuntu 24.04 LTS 6.8.0-40.40
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1013.14
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1012.13
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1008.11
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1010.10
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1012.14
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1009.10
  • linux-riscv Ubuntu 24.04 LTS 6.8.0-40.40.1

ubuntu advisories UBUNTU-CVE-2024-36979

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-2024:7490RHSA-2024:7489RHSA-2024:5102RHSA-2024:6567RHSA-2024:5101RHSA-2024:6206

  • kernel-rt Linux Micro 6.0 6.4.0-10.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-10.1
  • kernel-livepatch-MICRO-6-0-RT_Update_2 Linux Micro 6.0 1-1.1
  • kernel-source Linux Micro 6.0 6.4.0-19.1
  • kernel-default Linux Micro 6.0 6.4.0-19.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-19.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-livepatch-MICRO-6-0_Update_2 Linux Micro 6.0 1-1.1

suse advisories SUSE-SU-2025:20047-1SUSE-SU-2025:20044-1SUSE-SU-2025:0269-1SUSE-SU-2025:0268-1SUSE-SU-2025:0265-1SUSE-SU-2025:0263-1

  • kernel AlmaLinux 9 5.14.0-427.35.1.el9_4
  • rv AlmaLinux 9 5.14.0-427.35.1.el9_4
  • perf AlmaLinux 9 5.14.0-427.35.1.el9_4
  • rtla AlmaLinux 9 5.14.0-427.35.1.el9_4
  • bpftool AlmaLinux 9 7.3.0-427.35.1.el9_4
  • libperf AlmaLinux 9 5.14.0-427.35.1.el9_4
  • kernel-rt AlmaLinux 9 5.14.0-427.35.1.el9_4
  • kernel-64k AlmaLinux 9 5.14.0-427.35.1.el9_4

almalinux advisories ALSA-2024:6567ALSA-2024:5101ALSA-2024:5102

  • kernel Rocky Linux 9 5.14.0-427.35.1.el9_4.cloud.1.0
  • kernel Rocky Linux 8 4.18.0-553.16.1.el8_10.cloud.0.1
  • kernel Rocky Linux 9 5.14.0-427.35.1.el9_4
  • 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-2024:6567RXSA-2024:5101RLSA-2024:6567RLSA-2024:5102RLSA-2024:5101

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-2024-36979 updated cvss 6.6

kernel: net: bridge: mst: fix vlan use-after-free

  • 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: 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: no fix available
  • Red Hat CodeReady Linux Builder EUS (v.8.8) kernel-debuginfo-common-x86_64 4.18.0-477.70.1.el8_8, kernel-debuginfo-common-aarch64 4.18.0-477.70.1.el8_8, kernel-debuginfo-common-ppc64le 4.18.0-477.70.1.el8_8
    fixed: vendor fix RHSA-2024:6206
  • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-debuginfo-common-s390x 5.14.0-284.86.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.86.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.86.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.86.1.el9_2
    fixed: vendor fix RHSA-2024:7489
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.35.1.el9_4, perf 5.14.0-427.35.1.el9_4, rtla 5.14.0-427.35.1.el9_4, kernel-devel-matched 5.14.0-427.35.1.el9_4, kernel-64k-devel-matched 5.14.0-427.35.1.el9_4, kernel-debug-devel-matched 5.14.0-427.35.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:6567
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) perf 5.14.0-284.86.1.el9_2, rtla 5.14.0-284.86.1.el9_2, kernel-devel-matched 5.14.0-284.86.1.el9_2, kernel-64k-devel-matched 5.14.0-284.86.1.el9_2, kernel-debug-devel-matched 5.14.0-284.86.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.86.1.el9_2, +5 more
    fixed: vendor fix RHSA-2024:7489
  • 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 7.3.0-427.35.1.el9_4, kernel 5.14.0-427.35.1.el9_4, kernel-64k 5.14.0-427.35.1.el9_4, kernel-core 5.14.0-427.35.1.el9_4, kernel-tools 5.14.0-427.35.1.el9_4, python3-perf 5.14.0-427.35.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:6567
show 10 more
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) perf 4.18.0-477.70.1.el8_8, kernel 4.18.0-477.70.1.el8_8, bpftool 4.18.0-477.70.1.el8_8, kernel-core 4.18.0-477.70.1.el8_8, kernel-tools 4.18.0-477.70.1.el8_8, python3-perf 4.18.0-477.70.1.el8_8, +15 more
    fixed: vendor fix RHSA-2024:6206
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool 7.0.0-284.86.1.el9_2, kernel 5.14.0-284.86.1.el9_2, kernel-64k 5.14.0-284.86.1.el9_2, kernel-core 5.14.0-284.86.1.el9_2, kernel-tools 5.14.0-284.86.1.el9_2, python3-perf 5.14.0-284.86.1.el9_2, +28 more
    fixed: vendor fix RHSA-2024:7489
  • 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 5.14.0-427.35.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.35.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.35.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.35.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.35.1.el9_4
    fixed: vendor fix RHSA-2024:6567
  • 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 5.14.0-427.35.1.el9_4, kernel-rt-kvm 5.14.0-427.35.1.el9_4, kernel-rt-core 5.14.0-427.35.1.el9_4, kernel-rt-modules 5.14.0-427.35.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.35.1.el9_4, kernel-rt-debug-core 5.14.0-427.35.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:6567
  • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-core 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-modules 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-debug-core 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-modules-core 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-debug-modules 5.14.0-284.86.1.rt14.371.el9_2, +4 more Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-kvm 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-core 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-modules 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-debug-kvm 5.14.0-284.86.1.rt14.371.el9_2, kernel-rt-debug-core 5.14.0-284.86.1.rt14.371.el9_2, +6 more
    fixed: vendor fix RHSA-2024:7490
  • 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 5.14.0-427.35.1.el9_4, kernel-rt-core 5.14.0-427.35.1.el9_4, kernel-rt-modules 5.14.0-427.35.1.el9_4, kernel-rt-debug-core 5.14.0-427.35.1.el9_4, kernel-rt-modules-core 5.14.0-427.35.1.el9_4, kernel-rt-debug-modules 5.14.0-427.35.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:6567
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) kernel-doc 5.14.0-284.86.1.el9_2
    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

0.26% chance of exploitation in the next 30 days, higher than 17% 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 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
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.