tunnels: fix kasan splat when generating ipv4 pmtu error
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.9 and later | 5.10.191, 5.15.127, 6.1.46, 6.4.11, 6.5 | Patch available | CNA |
- Linux VendorLinux Affected 5.9 and later Fixed in 5.10.191, 5.15.127, 6.1.46, 6.4.11, 6.5 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.9 to before 5.10.191; 5.11 to before 5.15.127; 5.16 to before 6.1.46; 6.2 to before 6.4.11 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:* | 6.5 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.5:rc2:*:*:*:*:*:* | 6.5 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.5:rc3:*:*:*:*:*:* | 6.5 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.5:rc4:*:*:*:*:*:* | 6.5 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.5:rc5:*:*:*:*:*:* | 6.5 rc5 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.9 to before 5.10.191; 5.11 to before 5.15.127; 5.16 to before 6.1.46; 6.2 to before 6.4.11 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:* Versions 6.5 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.5:rc2:*:*:*:*:*:* Versions 6.5 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.5:rc3:*:*:*:*:*:* Versions 6.5 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.5:rc4:*:*:*:*:*:* Versions 6.5 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.5:rc5:*:*:*:*:*:* Versions 6.5 rc5 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.191, 5.15.127, 6.1.46, 6.4.11, 6.5
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Not affected: 2 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2023-53600
- 2026-10-03 Alias added: GHSA-qh3w-rq3m-fpq5
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-16 Priority changed: LOW → MEDIUM
References
Patch 5
- https://git.kernel.org/stable/c/5850c391fd7e25662334cb3cbf29a62bcbff1084
- https://git.kernel.org/stable/c/e95808121953410db8c59f0abfde70ac0d34222c
- https://git.kernel.org/stable/c/da5f42a6e7485fbb7a6dbd6a2b3045e19e4df5cc
- https://git.kernel.org/stable/c/fe6a9f7516735be9fdabab00e47ef7a3403a174d
- https://git.kernel.org/stable/c/6a7ac3d20593865209dceb554d8b3f094c6bd940
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2023-53600 · CVE Program
- CVE-2023-53600 · NVD
- FIRST EPSS
- GHSA-qh3w-rq3m-fpq5 · GitHub Advisory Database · CC BY 4.0
- CVE-2023-53600 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences