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Vulnerability · Published Oct 4, 2025 · Assigned by Linux

CVE-2023-53600tunnels: fix kasan splat when generating ipv4 pmtu error

Critical 9.1

In plain English

A critical-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.3%top 77.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: tunnels: fix kasan splat when generating ipv4 pmtu error If we try to emit an icmp error in response to a nonliner skb, we get BUG: KASAN: slab-out-of-bounds in ip_compute_csum+0x134/0x220 Read of size 4 at addr ffff88811c50db00 by task iperf3/1691 CPU: 2 PID: 1691 Comm: iperf3 Not tainted 6.5.0-rc3+ #309 [..] kasan_report+0x105/0x140 ip_compute_csum+0x134/0x220 iptunnel_pmtud_build_icmp+0x554/0x1020 skb_tunnel_check_pmtu+0x513/0xb80 vxlan_xmit_one+0x139e/0x2ef0 vxlan_xmit+0x1867/0x2760 dev_hard_start_xmit+0x1ee/0x4f0 br_dev_queue_push_xmit+0x4d1/0x660 [..] ip_compute_csum() cannot deal with nonlinear skbs, so avoid it. After this change, splat is gone and iperf3 is no longer stuck.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.52-1DEBIAN-CVE-2023-53600
Debian:13linux6.4.11-1DEBIAN-CVE-2023-53600
Debian:14linux6.4.11-1DEBIAN-CVE-2023-53600
Ubuntu:22.04:LTSlinux5.15.0-91.101UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-aws5.15.0-1051.56UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-azure5.15.0-1053.61UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1053.61.1UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-gcp5.15.0-1048.56UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-gke5.15.0-1048.53UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1034.40UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-ibm5.15.0-1044.47UBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1046.52UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-kvm5.15.0-1048.53UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-91.101UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1042.42UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1020.20UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1007.7UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-oracle5.15.0-1049.55UBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-raspi5.15.0-1044.47UBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53600
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2023-53600
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1027.31UBUNTU-CVE-2023-53600

Affected products (as reported)

VendorProductVersions
Linux Linux 4cb47a8644cc9eb8ec81190a50e79e6530d0297f – before 5850c391fd7e25662334cb3cbf29a62bcbff10844cb47a8644cc9eb8ec81190a50e79e6530d0297f – before e95808121953410db8c59f0abfde70ac0d34222c4cb47a8644cc9eb8ec81190a50e79e6530d0297f – before da5f42a6e7485fbb7a6dbd6a2b3045e19e4df5cc4cb47a8644cc9eb8ec81190a50e79e6530d0297f – before fe6a9f7516735be9fdabab00e47ef7a3403a174d4cb47a8644cc9eb8ec81190a50e79e6530d0297f – before 6a7ac3d20593865209dceb554d8b3f094c6bd940
Linux Linux 5.9

References