Description
In the Linux kernel, the following vulnerability has been resolved:
udp: Fix wildcard bind conflict check when using hash2
When binding a udp_sock to a local address and port, UDP uses
two hashes (udptable->hash and udptable->hash2) for collision
detection. The current code switches to "hash2" when
hslot->count > 10.
"hash2" is keyed by local address and local port.
"hash" is keyed by local port only.
The issue can be shown in the following bind sequence (pseudo code):
bind(fd1, "[fd00::1]:8888")
bind(fd2, "[fd00::2]:8888")
bind(fd3, "[fd00::3]:8888")
bind(fd4, "[fd00::4]:8888")
bind(fd5, "[fd00::5]:8888")
bind(fd6, "[fd00::6]:8888")
bind(fd7, "[fd00::7]:8888")
bind(fd8, "[fd00::8]:8888")
bind(fd9, "[fd00::9]:8888")
bind(fd10, "[fd00::10]:8888")
/* Correctly return -EADDRINUSE because "hash" is used
* instead of "hash2". udp_lib_lport_inuse() detects the
* conflict.
*/
bind(fail_fd, "[::]:8888")
/* After one more socket is bound to "[fd00::11]:8888",
* hslot->count exceeds 10 and "hash2" is used instead.
*/
bind(fd11, "[fd00::11]:8888")
bind(fail_fd, "[::]:8888") /* succeeds unexpectedly */
The same issue applies to the IPv4 wildcard address "0.0.0.0"
and the IPv4-mapped wildcard address "::ffff:0.0.0.0". For
example, if there are existing sockets bound to
"192.168.1.[1-11]:8888", then binding "0.0.0.0:8888" or
"[::ffff:0.0.0.0]:8888" can also miss the conflict when
hslot->count > 10.
TCP inet_csk_get_port() already has the correct check in
inet_use_bhash2_on_bind(). Rename it to
inet_use_hash2_on_bind() and move it to inet_hashtables.h
so udp.c can reuse it in this fix.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 2.6.33 | 6.1.168 |
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 | 6.19.11-1 | — |
| Debian 13 | linux | 6.12.85-1 | — |
| Debian 12 | linux | 6.1.170-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1028.33 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu 25.10 | linux +8 | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-136.136 | USN-8567-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1061.64 | USN-8595-2 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1063.71 | USN-8606-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1062.69 | USN-8607-1 |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1064.72 | USN-8567-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1059.67 | USN-8567-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1046.50 | USN-8567-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1061.62 | USN-8574-3 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-136.136.2 | USN-8574-2 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1059.62 | USN-8596-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1059.62.1 | USN-8596-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1030.31 | USN-8574-3 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1058.61 | USN-8574-2 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1061.65 | USN-8665-1 |
| Ubuntu 24.04 LTS | linux-riscv +27 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-vmware | 6.8.0-1008.8 | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1033.34 | USN-8574-3 |
| Ubuntu 22.04 LTS | linux +49 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1061.64~22.04.1 | USN-8595-3 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1063.71~22.04.1 | USN-8606-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1062.69~22.04.1 | USN-8609-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1064.72~22.04.1 | USN-8567-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-136.136~22.04.1 | USN-8619-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1061.62~22.04.1 | USN-8574-3 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-136.136.2~22.04.1 | USN-8574-2 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1059.62~22.04.1 | USN-8596-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1058.61~22.04.1 | USN-8595-1 |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-136.136~22.04.3 | — |
Show 18 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2050.52 | USN-8665-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1056.57 | USN-8567-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1056.57~22.04.2 | USN-8567-1 |
| 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 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1061.64+fips1 | USN-8595-3 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1063.71+fips2 | USN-8608-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-136.136+fips2 | USN-8574-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1064.72+fips1 | USN-8574-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux +21 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux +12 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux +7 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux +3 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | rv +76 | 6.12.0-211.52.1.el10_2 | RHSA-2026:64775 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | kernel | 6.12.0-211.52.1.el10_2 | RLSA-2026:64775 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +4 | 6.4.0-150700.53.73.2 | SUSE-SU-2026:3166-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.73.2.150700.17.41.4 | SUSE-SU-2026:3166-1 |
| SLES 15 SP7 | kernel-docs +2 | 6.4.0-150700.53.73.1 | SUSE-SU-2026:3166-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.2 | kernel-syms +1 | 6.12.0-160000.33.1 | SUSE-SU-2026:21834-1 |
| SLE Micro 6.1 | kernel-rt +2 | 6.4.0-50.1 | SUSE-SU-2026:22904-1, SUSE-SU-2026:22903-1 |
| SLE Micro 6.1 | kernel-source +1 | 6.4.0-50.2 | SUSE-SU-2026:22904-1, SUSE-SU-2026:22903-1 |
| SLE Micro 6.0 | kernel-rt +2 | 6.4.0-50.1 | SUSE-SU-2026:22810-1, SUSE-SU-2026:22809-1 |
| SLE Micro 6.0 | kernel-source +1 | 6.4.0-50.2 | SUSE-SU-2026:22810-1, SUSE-SU-2026:22809-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.73.2 | SUSE-SU-2026:3166-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_18 | 1-150700.1.5.1 | SUSE-SU-2026:3130-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_19 | 1-150700.15.3.4 | SUSE-SU-2026:3166-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.67.1 | SUSE-SU-2026:3130-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.18.25-52.107 +2 | 1:1.0-0.amzn2023 | ALAS2023-2026-1746, ALAS2023-2026-1681, ALAS2023-2026-1646 |
| Amazon Linux 2023 | perf +14 | 1:6.1.168-202.320.amzn2023 | ALAS2023-2026-1681 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.80-105.147.amzn2023 | ALAS2023-2026-1646 |
| Amazon Linux 2023 | perf6.18 +11 | 1:6.18.25-52.107.amzn2023 | ALAS2023-2026-1746 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.134.1-2 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-204.92.4.2.el10uek | ELSA-2026-50372 |
Advisories 33
- WID-SEC-2026-1252 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- SSA-457936 SSA-457936: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.7 Siemens ProductCERT · Nov 10, 2026
- USN-8574-3 linux-ibm, linux-ibm-6.8, linux-nvidia-tegra, linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8595-3 linux-aws-6.8, linux-aws-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8574-2 linux-fips, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8596-1 linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8665-1 linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8608-1 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8574-1 linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8595-2 linux-aws vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8595-1 linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8567-1 linux, linux-gcp, linux-gcp-6.8, linux-gke, linux-gkeop, linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8606-1 linux-azure, linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8607-1 linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8619-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8609-1 linux-azure-fde-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- ICSA-26-295-11 Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP CISA ICS & IT advisories · Oct 22, 2026
- RHSA-2026:64775 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- SSA-019113 SSA-019113: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.6 Siemens ProductCERT · Oct 13, 2026
- SSA-082556 SSA-082556: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.5 Siemens ProductCERT · Oct 13, 2026
- RLSA-2026:64775 Important: kernel security, bug fix, and enhancement update Rocky Linux Security Advisories · Sep 9, 2026
- ALAS2023-2026-1681 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 29, 2026
- SUSE-SU-2026:22903-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 28, 2026
- SUSE-SU-2026:22904-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 28, 2026
- SUSE-SU-2026:22809-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 28, 2026
- SUSE-SU-2026:22810-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 28, 2026
- ICSA-26-209-04 Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP CISA ICS & IT advisories · Jul 28, 2026
- SUSE-SU-2026:3166-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 22, 2026
- SUSE-SU-2026:3130-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 21, 2026
- SUSE-SU-2026:21834-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- ELSA-2026-50372 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 2, 2026
- ALAS2023-2026-1746 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 1, 2026
- ALAS2023-2026-1646 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 11, 2026
References
- https://git.kernel.org/stable/c/d6ace0dbcbb7fd285738bb87b42b71b01858c952
- https://git.kernel.org/stable/c/2297e38114316b26ae02f2d205c49b5511c5ed55
- https://git.kernel.org/stable/c/f1bed05a832ae79be5f7a105da56810eaa59a5f1
- https://git.kernel.org/stable/c/18d84c45def3671d5c89fbdd5d4ab8a3217fe4b4
- https://git.kernel.org/stable/c/0a360f7f73a06ac88f18917055fbcc79694252d7
- https://git.kernel.org/stable/c/e537dd15d0d4ad989d56a1021290f0c674dd8b28