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Unscored CVE-2024-36889 EUVD-2024-36241

mptcp: ensure snd_nxt is properly initialized on connect

Published May 30, 2024 · Updated May 11, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.2 Package: linux-azure-fips Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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

mptcp: ensure snd_nxt is properly initialized on connect

Christoph reported a splat hinting at a corrupted snd_una:

WARNING: CPU: 1 PID: 38 at net/mptcp/protocol.c:1005 __mptcp_clean_una+0x4b3/0x620 net/mptcp/protocol.c:1005
Modules linked in:
CPU: 1 PID: 38 Comm: kworker/1:1 Not tainted 6.9.0-rc1-gbbeac67456c9 #59
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:__mptcp_clean_una+0x4b3/0x620 net/mptcp/protocol.c:1005
Code: be 06 01 00 00 bf 06 01 00 00 e8 a8 12 e7 fe e9 00 fe ff ff e8
8e 1a e7 fe 0f b7 ab 3e 02 00 00 e9 d3 fd ff ff e8 7d 1a e7 fe
<0f> 0b 4c 8b bb e0 05 00 00 e9 74 fc ff ff e8 6a 1a e7 fe 0f 0b e9
RSP: 0018:ffffc9000013fd48 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8881029bd280 RCX: ffffffff82382fe4
RDX: ffff8881003cbd00 RSI: ffffffff823833c3 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: fefefefefefefeff R12: ffff888138ba8000
R13: 0000000000000106 R14: ffff8881029bd908 R15: ffff888126560000
FS: 0000000000000000(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f604a5dae38 CR3: 0000000101dac002 CR4: 0000000000170ef0
Call Trace:
<TASK>
__mptcp_clean_una_wakeup net/mptcp/protocol.c:1055 [inline]
mptcp_clean_una_wakeup net/mptcp/protocol.c:1062 [inline]
__mptcp_retrans+0x7f/0x7e0 net/mptcp/protocol.c:2615
mptcp_worker+0x434/0x740 net/mptcp/protocol.c:2767
process_one_work+0x1e0/0x560 kernel/workqueue.c:3254
process_scheduled_works kernel/workqueue.c:3335 [inline]
worker_thread+0x3c7/0x640 kernel/workqueue.c:3416
kthread+0x121/0x170 kernel/kthread.c:388
ret_from_fork+0x44/0x50 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
</TASK>

When fallback to TCP happens early on a client socket, snd_nxt
is not yet initialized and any incoming ack will copy such value
into snd_una. If the mptcp worker (dumbly) tries mptcp-level
re-injection after such ack, that would unconditionally trigger a send
buffer cleanup using 'bad' snd_una values.

We could easily disable re-injection for fallback sockets, but such
dumb behavior already helped catching a few subtle issues and a very
low to zero impact in practice.

Instead address the issue always initializing snd_nxt (and write_seq,
for consistency) at connect time.

Affected products

VendorProductAffectedFixed
Linux Linux 5.9 5.10.218

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.8.11-1 —
Debian 13 linux 6.8.11-1 —
Debian 12 linux 6.1.94-1 —
Debian 11 linux 5.10.218-1 DSA-5703-1
Debian 10 linux-5.10 5.10.218-1~deb10u1 DLA-3843-1
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1050.52 —
Ubuntu 24.04 LTS linux 6.8.0-40.40 USN-6949-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1013.14 USN-6949-1
Ubuntu 24.04 LTS linux-azure 6.8.0-1012.14 USN-6952-2
Ubuntu 24.04 LTS linux-gcp 6.8.0-1012.13 USN-6949-1
Ubuntu 24.04 LTS linux-gke 6.8.0-1008.11 USN-6949-1
Ubuntu 24.04 LTS linux-ibm +2 6.8.0-1010.10 USN-6955-1, USN-6952-1, USN-6949-1
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1011.11 USN-6949-1
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1011.11.1 USN-6952-1
Ubuntu 24.04 LTS linux-raspi 6.8.0-1009.10 USN-6949-2
Ubuntu 24.04 LTS linux-riscv +1 6.8.0-40.40.1 USN-6949-2
Ubuntu 22.04 LTS linux +1 5.15.0-118.128 USN-6950-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1067.73 USN-6950-1
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1013.14~22.04.1 —
Ubuntu 22.04 LTS linux-azure 5.15.0-1070.79 USN-6956-1
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1012.14~22.04.1 —
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1070.79.1 USN-6956-1
Ubuntu 22.04 LTS linux-gcp 5.15.0-1066.74 USN-6950-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1012.13~22.04.1 —
Ubuntu 22.04 LTS linux-gke 5.15.0-1064.70 USN-6950-1
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1050.57 USN-6950-1
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-40.40~22.04.3 —
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1060.63 USN-6950-2
Ubuntu 22.04 LTS linux-ibm-6.8 +1 6.8.0-1010.10~22.04.1 —
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1062.68 USN-6950-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1064.69 USN-6950-1
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1062.63 USN-6950-1
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1011.11~22.04.1 USN-6949-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1027.27 —
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1015.15 —
Ubuntu 22.04 LTS linux-oracle 5.15.0-1065.71 USN-6950-3
Ubuntu 22.04 LTS linux-riscv +31 No fix yet —
Ubuntu 22.04 LTS linux-riscv-6.8 +1 6.8.0-40.40.1~22.04.1 —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1035.39 USN-7019-1
Ubuntu 20.04 LTS linux-aws-5.15 5.15.0-1067.73~20.04.1 USN-6950-2
Ubuntu 20.04 LTS linux-azure-5.15 5.15.0-1070.79~20.04.1 USN-6956-1
Ubuntu 20.04 LTS linux-azure-fde-5.15 5.15.0-1070.79~20.04.1.1 USN-6956-1
Ubuntu 20.04 LTS linux-gcp-5.15 5.15.0-1066.74~20.04.1 USN-6950-1
Ubuntu 20.04 LTS linux-gke +26 No fix yet —
Ubuntu 20.04 LTS linux-gkeop-5.15 5.15.0-1050.57~20.04.1 USN-6950-2
Ubuntu 20.04 LTS linux-hwe-5.15 +1 5.15.0-118.128~20.04.1 USN-6950-4, USN-6950-1
Ubuntu 20.04 LTS linux-ibm-5.15 5.15.0-1060.63~20.04.1 USN-6950-2
Ubuntu 20.04 LTS linux-intel-iotg-5.15 5.15.0-1062.68~20.04.1 USN-6950-1
Ubuntu 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1027.27~20.04.1 —
Ubuntu 20.04 LTS linux-oracle-5.15 5.15.0-1065.71~20.04.1 USN-6957-1
Ubuntu 20.04 LTS linux-riscv-5.15 5.15.0-1063.67~20.04.1 —
Ubuntu 18.04 LTS linux-gcp +13 No fix yet —
Show 6 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2008.8 —
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1006.6 —
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1060.62 —
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1068.76 —
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1006.6~22.04.1 —
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-78.78+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1067.73+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1070.79+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-118.128+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1066.74+fips1 —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
ReleasePackageFixed inAdvisory
RHEL 9 bpftool 7.3.0-427.40.1.el9_4 RHSA-2024:8162
RHEL 9 rv +64 5.14.0-427.40.1.el9_4 RHSA-2024:8162
RHEL 8 kernel-rt +12 4.18.0-553.16.1.rt7.357.el8_10 RHSA-2024:5102
RHEL 8 perf +26 4.18.0-553.16.1.el8_10 RHSA-2024:5101
Show 5 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
RHEL 9.2 EUS bpftool 7.0.0-284.90.1.el9_2 RHSA-2024:8613
RHEL 9.2 EUS kernel-rt +14 5.14.0-284.90.1.rt14.375.el9_2 RHSA-2024:8614
RHEL 9.2 EUS perf +48 5.14.0-284.90.1.el9_2 RHSA-2024:8613
RHEL 8.8 EUS perf +26 4.18.0-477.81.1.el8_8 RHSA-2024:10262
RHEL 8.6 TUS perf +17 4.18.0-372.124.1.el8_6 RHSA-2024:6998
RHEL 8.6 E4S perf +25 4.18.0-372.124.1.el8_6 RHSA-2024:6998
RHEL 8.6 AUS perf +17 4.18.0-372.124.1.el8_6 RHSA-2024:6998

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 9 bpftool 7.3.0-427.40.1.el9_4 ALSA-2024:8162
AlmaLinux 9 rv +60 5.14.0-427.40.1.el9_4 ALSA-2024:8162
AlmaLinux 8 kernel-rt +11 4.18.0-553.16.1.rt7.357.el8_10 ALSA-2024:5102
AlmaLinux 8 perf +24 4.18.0-553.16.1.el8_10 ALSA-2024:5101

Rocky Linux

Errata ↗
ReleasePackageFixed inAdvisory
Rocky Linux 9 kernel 5.14.0-427.40.1.el9_4 RLSA-2024:8162
Rocky Linux 8 kernel 4.18.0-553.16.1.el8_10 RXSA-2024:5101, RLSA-2024:5101
Rocky Linux 8 kernel-rt 4.18.0-553.16.1.rt7.357.el8_10 RLSA-2024:5102
ReleasePackageFixed inAdvisory
SLES 15 SP6 kernel-64kb +5 6.4.0-150600.23.17.1 SUSE-SU-2024:2802-1
SLES 15 SP6 kernel-azure +1 6.4.0-150600.8.8.2 SUSE-SU-2024:2896-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.17.1.150600.12.6.2 SUSE-SU-2024:2802-1
SLES 15 SP6 kernel-docs 6.4.0-150600.23.17.3 SUSE-SU-2024:2802-1
SLES 15 SP6 kernel-syms-azure 6.4.0-150600.8.8.1 SUSE-SU-2024:2896-1
SLES 15 SP5 kernel-64kb +5 5.14.21-150500.55.73.1 SUSE-SU-2024:2939-1
SLES 15 SP5 kernel-azure +2 5.14.21-150500.33.63.1 SUSE-SU-2024:2947-1
SLES 15 SP5 kernel-default-base 5.14.21-150500.55.73.1.150500.6.33.8 SUSE-SU-2024:2939-1
SLES 15 SP5 kernel-docs 5.14.21-150500.55.73.2 SUSE-SU-2024:2939-1
Show 6 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLE Micro 6.0 kernel-default-base 6.4.0-17.1.1.51 SUSE-SU-2025:20008-1
SLE Micro 6.0 kernel-rt +1 6.4.0-9.1 SUSE-SU-2025:20028-1
SLE Micro 6.0 kernel-source +2 6.4.0-18.1 SUSE-SU-2025:20008-1
SLE Micro 5.5 kernel-default 5.14.21-150500.55.73.1 SUSE-SU-2024:2939-1
SLE Micro 5.5 kernel-default-base 5.14.21-150500.55.73.1.150500.6.33.8 SUSE-SU-2024:2939-1
SLE Micro 5.5 kernel-rt +1 5.14.21-150500.13.64.1 SUSE-SU-2024:2894-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.17.1 SUSE-SU-2024:2802-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_1 1-150600.1.5.1 SUSE-SU-2024:2973-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_3 1-150600.13.3.1 SUSE-SU-2024:2802-1
SLE Live Patching 15 SP5 kernel-default 5.14.21-150500.55.73.1 SUSE-SU-2024:2939-1
SLE Live Patching 15 SP5 kernel-livepatch-SLE15-SP5_Update_17 +1 1-150500.11.3.1 SUSE-SU-2024:2939-1, SUSE-SU-2024:2894-1
SUSE Real Time Module 15 SP6 kernel-rt +3 6.4.0-150600.10.5.1 SUSE-SU-2024:2973-1
SUSE Real Time Module 15 SP5 kernel-rt +3 5.14.21-150500.13.64.1 SUSE-SU-2024:2894-1
ReleasePackageFixed inAdvisory
openSUSE Leap 15.6 dtb-aarch64 +9 6.4.0-150600.23.17.1 SUSE-SU-2024:2802-1
openSUSE Leap 15.6 kernel-azure +1 6.4.0-150600.8.8.2 SUSE-SU-2024:2896-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.17.1.150600.12.6.2 SUSE-SU-2024:2802-1
openSUSE Leap 15.6 kernel-docs 6.4.0-150600.23.17.3 SUSE-SU-2024:2802-1
openSUSE Leap 15.6 kernel-rt +3 6.4.0-150600.10.5.1 SUSE-SU-2024:2973-1
openSUSE Leap 15.6 kernel-syms-azure 6.4.0-150600.8.8.1 SUSE-SU-2024:2896-1
openSUSE Leap 15.5 dtb-aarch64 +9 5.14.21-150500.55.73.1 SUSE-SU-2024:2939-1
openSUSE Leap 15.5 kernel-azure +2 5.14.21-150500.33.63.1 SUSE-SU-2024:2947-1
openSUSE Leap 15.5 kernel-default-base 5.14.21-150500.55.73.1.150500.6.33.8 SUSE-SU-2024:2939-1
openSUSE Leap 15.5 kernel-docs 5.14.21-150500.55.73.2 SUSE-SU-2024:2939-1
openSUSE Leap 15.5 kernel-rt +3 5.14.21-150500.13.64.1 SUSE-SU-2024:2894-1
Show 1 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
openSUSE Leap Micro 5.5 kernel-default 5.14.21-150500.55.73.1 SUSE-SU-2024:2939-1
openSUSE Leap Micro 5.5 kernel-default-base 5.14.21-150500.55.73.1.150500.6.33.8 SUSE-SU-2024:2939-1
openSUSE Leap Micro 5.5 kernel-rt 5.14.21-150500.13.64.1 SUSE-SU-2024:2894-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.1.91-99.172 1.0-0.amzn2023 ALAS2023-2024-643
Amazon Linux 2023 perf +14 6.1.91-99.172.amzn2023 ALAS2023-2024-643

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 bpftool 7.3.0-427.40.1.el9_4 ELSA-2024-8162
Oracle Linux 9 rv +27 5.14.0-427.40.1.el9_4 ELSA-2024-8162
Oracle Linux 8 perf +19 4.18.0-553.16.1.el8_10 ELSA-2024-5101

Advisories 43

References