Critical 9.1Published Oct 4, 2025

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

Updated under an hour ago (Oct 28, 2026, 4:30 AM ET)

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Exploited in the last 30 days

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.

CVSS: 9.1 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 15, 2026
First seen by InfoSec Signals: Oct 15, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 4cb47a8644cc9eb8ec81190a50e79e6530d0297f before 5850c391fd7e25662334cb3cbf29a62bcbff1084; from 4cb47a8644cc9eb8ec81190a50e79e6530d0297f before e95808121953410db8c59f0abfde70ac0d34222c; from 4cb47a8644cc9eb8ec81190a50e79e6530d0297f before da5f42a6e7485fbb7a6dbd6a2b3045e19e4df5cc; from 4cb47a8644cc9eb8ec81190a50e79e6530d0297f before fe6a9f7516735be9fdabab00e47ef7a3403a174d; from 4cb47a8644cc9eb8ec81190a50e79e6530d0297f before 6a7ac3d20593865209dceb554d8b3f094c6bd940	CNA record
linux linux_kernel linux:linux_kernel	from 5.9 before 5.10.191; from 5.11 before 5.15.127; from 5.16 before 6.1.46; from 6.2 before 6.4.11; 6.5; 6.5; 6.5; 6.5; and 1 more ranges	NVD

References

References

https://git.kernel.org/stable/c/5850c391fd7e25662334cb3cbf29a62bcbff1084	patch
https://git.kernel.org/stable/c/e95808121953410db8c59f0abfde70ac0d34222c	patch
https://git.kernel.org/stable/c/da5f42a6e7485fbb7a6dbd6a2b3045e19e4df5cc	patch
https://git.kernel.org/stable/c/fe6a9f7516735be9fdabab00e47ef7a3403a174d	patch
https://git.kernel.org/stable/c/6a7ac3d20593865209dceb554d8b3f094c6bd940	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.