Description
In the Linux kernel, the following vulnerability has been resolved:
kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg().
syzkaller found a memory leak in kcm_sendmsg(), and commit c821a88bd720
("kcm: Fix memory leak in error path of kcm_sendmsg()") suppressed it by
updating kcm_tx_msg(head)->last_skb if partial data is copied so that the
following sendmsg() will resume from the skb.
However, we cannot know how many bytes were copied when we get the error.
Thus, we could mess up the MSG_MORE queue.
When kcm_sendmsg() fails for SOCK_DGRAM, we should purge the queue as we
do so for UDP by udp_flush_pending_frames().
Even without this change, when the error occurred, the following sendmsg()
resumed from a wrong skb and the queue was messed up. However, we have
yet to get such a report, and only syzkaller stumbled on it. So, this
can be changed safely.
Note this does not change SOCK_SEQPACKET behaviour.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.6 | 4.14.326 |
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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.5.6-1 | — |
| Debian 13 | linux | 6.5.6-1 | — |
| Debian 12 | linux | 6.1.55-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1035.37 | — |
| Ubuntu 24.04 LTS | linux-riscv +10 | No fix yet | — |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-94.104 | — |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1053.58 | — |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1056.64 | — |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1056.64.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1051.59 | — |
| Ubuntu 22.04 LTS | linux-gke +1 | 5.15.0-1050.55 | — |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1036.42 | — |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1046.49 | — |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1047.53 | — |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1044.44 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1022.22 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1009.9 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1051.57 | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1027.31 | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-169.187 | — |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1116.126 | — |
| Ubuntu 20.04 LTS | linux-aws-5.15 | 5.15.0-1053.58~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1121.128 | — |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1056.64~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-bluefield | 5.4.0-1076.82 | — |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1120.129 | — |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1051.59~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-94.104~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-ibm | 5.4.0-1063.68 | — |
| Ubuntu 20.04 LTS | linux-ibm-5.15 | 5.15.0-1046.49~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1048.54~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-iot | 5.4.0-1028.29 | — |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1104.111 | — |
| Ubuntu 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1022.22~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1115.124 | — |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1051.57~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1100.112 | — |
| Ubuntu 20.04 LTS | linux-riscv-5.15 | 5.15.0-1049.53~20.04.2 | — |
| Ubuntu 20.04 LTS | linux-xilinx-zynqmp | 5.4.0-1035.39 | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1046.48 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1054.60 | — |
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1053.58+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-94.104+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1055.63+fips2 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-aws-fips | 5.4.0-1116.126+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1121.128+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips | 5.4.0-1090.100 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1120.129+fips1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux +5 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux-aws-5.4 | 5.4.0-1116.126~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-azure-5.4 | 5.4.0-1121.128~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-gcp-5.4 | 5.4.0-1120.129~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-hwe-5.4 | 5.4.0-169.187~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-ibm-5.4 | 5.4.0-1063.68~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-oracle-5.4 | 5.4.0-1115.124~18.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux-raspi-5.4 | 5.4.0-1100.112~18.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-gcp +4 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.28.1 | SUSE-SU-2026:0315-1 |
| SLES 15 SP7 | kernel-azure +2 | 6.4.0-150700.20.24.1 | SUSE-SU-2026:0281-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.28.1.150700.17.19.1 | SUSE-SU-2026:0315-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.84.1 | SUSE-SU-2026:0293-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.84.1.150600.12.38.1 | SUSE-SU-2026:0293-1 |
| SLES 12 SP5 | kernel-syms +2 | 4.12.14-122.293.1 | SUSE-SU-2026:0473-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | kernel-default-base | 6.4.0-150600.23.84.1.150600.12.38.1 | SUSE-SU-2026:0293-1 |
| SLES for SAP 15 SP6 | kernel-docs +4 | 6.4.0-150600.23.84.1 | SUSE-SU-2026:0293-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-39.1.21.16 | SUSE-SU-2026:20498-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-40.1 | SUSE-SU-2026:20876-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-39.1 | SUSE-SU-2026:20498-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-39.1.21.16 | SUSE-SU-2026:20477-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-40.1 | SUSE-SU-2026:20845-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-39.1 | SUSE-SU-2026:20477-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.28.1 | SUSE-SU-2026:0315-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_8 | 1-150700.1.3.1 | SUSE-SU-2026:0278-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_8 | 1-150700.15.3.1 | SUSE-SU-2026:0315-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.84.1 | SUSE-SU-2026:0293-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_19 | 1-150600.13.3.1 | SUSE-SU-2026:0293-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.293.1 | SUSE-SU-2026:0473-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_77 | 1-8.3.1 | SUSE-SU-2026:0473-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.28.1 | SUSE-SU-2026:0278-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.84.1 | SUSE-SU-2026:0293-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.84.1.150600.12.38.1 | SUSE-SU-2026:0293-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.1.55-75.123 | 1.0-0.amzn2023 | ALAS2023-2023-356 |
| Amazon Linux 2023 | perf +12 | 6.1.55-75.123.amzn2023 | ALAS2023-2023-356 |
| Amazon Linux 2 | kernel-livepatch-4.14.326-245.539 | 1.0-0.amzn2 | ALAS2-2023-2264 |
| Amazon Linux 2 | perf +8 | 4.14.326-245.539.amzn2 | ALAS2-2023-2264 |
Advisories 12
- WID-SEC-2025-2765 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 12, 2026
- SUSE-SU-2026:20876-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 31, 2026
- SUSE-SU-2026:20845-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 28, 2026
- SUSE-SU-2026:20498-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20477-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0293-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0281-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0278-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0315-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0473-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- ALAS2023-2023-356 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 11, 2026
- ALAS2-2023-2264 Important: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Feb 11, 2026
References
- https://git.kernel.org/stable/c/21b467735b0888a8daa048f83d3b9b50fdab71ce
- https://git.kernel.org/stable/c/d4b8f380b0a041ee6a84fdac14127d8fe1dcad7b
- https://git.kernel.org/stable/c/1ce8362b4ac6b8e65fd04a22ea37ec776ee1ec5b
- https://git.kernel.org/stable/c/2e18493c421428a936946c452461b8e979088f17
- https://git.kernel.org/stable/c/55d2e7c1ab8eaa7b62575b8a4194132795d1f9fc
- https://git.kernel.org/stable/c/e5b28ce127a690f3acc49a6a342e6c9442c9edd6
- https://git.kernel.org/stable/c/992b2ac783aad360b98ed9d4686e86176a20f6f1
- https://git.kernel.org/stable/c/a22730b1b4bf437c6bbfdeff5feddf54be4aeada