CVE-2025-68775: net/handshake: duplicate handshake cancellations leak socket

Published Jan 13, 2026
·
Updated

In the Linux kernel, the following vulnerability has been resolved:

net/handshake: duplicate handshake cancellations leak socket

When a handshake request is cancelled it is removed from the handshakenet->hnrequests list, but it is still present in the handshakerhashtbl until it is destroyed.

If a second cancellation request arrives for the same handshake request, then removepending() will return false... and assuming HANDSHAKEFREQCOMPLETED isn't set in req->hrflags, we'll continue processing through the outtrue label, where we put another reference on the sock and a refcount underflow occurs.

This can happen for example if a handshake times out - particularly if the SUNRPC client sends the AUTHTLS probe to the server but doesn't follow it up with the ClientHello due to a problem with tlshd. When the timeout is hit on the server, the server will send a FIN, which triggers a cancellation request via xsresettransport(). When the timeout is hit on the client, another cancellation request happens via xstlshandshakesync().

Add a testandsetbit(HANDSHAKEFREQCOMPLETED) in the pending cancel path so duplicate cancels can be detected.

Affected Software

152 affected componentsFixes available
linux-kernel
Microsoft azl3 kernel 6.6.119.3-3
Patch available
debian/linux
6.1.176-16.1.190-16.12.107-16.12.115-27.2.12-17.2.15-1
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.8*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.8*
ubuntu/linux-gke*
ubuntu/linux-gke-5.15*
ubuntu/linux-gkeop*
ubuntu/linux-gkeop-5.15*
ubuntu/linux-hwe-5.11*
ubuntu/linux-hwe-5.13*
ubuntu/linux-hwe-5.8*
ubuntu/linux-intel-5.13*
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.8*
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8<6.8.0-1052.55~22.04.1
6.8.0-1052.55~22.04.1
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8<6.8.0-1059.65~22.04.1
6.8.0-1059.65~22.04.1
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8<6.8.0-1058.65~22.04.1
6.8.0-1058.65~22.04.1
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8<6.8.0-1054.57~22.04.1
6.8.0-1054.57~22.04.1
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-hwe-6.8<6.8.0-110.110~22.04.1
6.8.0-110.110~22.04.1
ubuntu/linux-ibm-6.8<6.8.0-1051.51~22.04.1
6.8.0-1051.51~22.04.1
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8<6.8.0-110.110.1~22.04.1
6.8.0-110.110.1~22.04.1
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8<6.8.0-1051.54~22.04.1
6.8.0-1051.54~22.04.1
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8<6.8.0-1049.50~22.04.1
6.8.0-1049.50~22.04.1
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8<6.8.0-110.110~22.04.1
6.8.0-110.110~22.04.1
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-realtime-6.8<6.8.1-1047.48~22.04.1
6.8.1-1047.48~22.04.1
ubuntu/linux<6.8.0-110.110
6.8.0-110.110
ubuntu/linux-aws<6.8.0-1052.55
6.8.0-1052.55
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17<6.17.0-1012.12~24.04.1
6.17.0-1012.12~24.04.1
ubuntu/linux-azure<6.8.0-1054.60
6.8.0-1054.60
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17<6.17.0-1013.13~24.04.1
6.17.0-1013.13~24.04.1
ubuntu/linux-azure-fde<6.8.0-1058.65
6.8.0-1058.65
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-nvidia*
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp<6.8.0-1054.57
6.8.0-1054.57
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-6.17<6.17.0-1012.12~24.04.1
6.17.0-1012.12~24.04.1
ubuntu/linux-gke<6.8.0-1050.56
6.8.0-1050.56
ubuntu/linux-gkeop<6.8.0-1037.40
6.8.0-1037.40
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17<6.17.0-22.22~24.04.1
6.17.0-22.22~24.04.1
ubuntu/linux-ibm<6.8.0-1051.51
6.8.0-1051.51
ubuntu/linux-lowlatency<6.8.0-110.110.1
6.8.0-110.110.1
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia<6.8.0-1051.54
6.8.0-1051.54
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17<6.17.0-1018.18
6.17.0-1018.18
ubuntu/linux-nvidia-lowlatency<6.8.0-1051.54.1
6.8.0-1051.54.1
ubuntu/linux-nvidia-tegra<6.8.0-1022.22
6.8.0-1022.22
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17<6.17.0-1020.20
6.17.0-1020.20
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle<6.8.0-1049.50
6.8.0-1049.50
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17<6.17.0-1011.11~24.04.1
6.17.0-1011.11~24.04.1
ubuntu/linux-raspi<6.8.0-1052.56
6.8.0-1052.56
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17<6.17.0-22.22.1~24.04.1
6.17.0-22.22.1~24.04.1
ubuntu/linux-xilinx<6.8.0-1028.29
6.8.0-1028.29
ubuntu/linux-bluefield<6.8.0-1017.21
6.8.0-1017.21
ubuntu/linux-raspi-realtime<6.8.0-2042.43
6.8.0-2042.43
ubuntu/linux-realtime<6.8.1-1047.48
6.8.1-1047.48
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17<6.17.0-1010.11~24.04.1
6.17.0-1010.11~24.04.1
ubuntu/linux-aws-fips<6.8.0-1052.55+fips1
6.8.0-1052.55+fips1
ubuntu/linux-azure-fips<6.8.0-1053.59+fips1
6.8.0-1053.59+fips1
ubuntu/linux-fips<6.8.0-110.110+fips2
6.8.0-110.110+fips2
ubuntu/linux-gcp-fips<6.8.0-1054.57+fips1
6.8.0-1054.57+fips1
ubuntu/linux<6.17.0-22.22
6.17.0-22.22
ubuntu/linux-aws<6.17.0-1012.12
6.17.0-1012.12
ubuntu/linux-azure<6.17.0-1013.13
6.17.0-1013.13
ubuntu/linux-azure-fde*
ubuntu/linux-gcp<6.17.0-1012.12
6.17.0-1012.12
ubuntu/linux-oracle<6.17.0-1011.11
6.17.0-1011.11
ubuntu/linux-raspi<6.17.0-1013.13
6.17.0-1013.13
ubuntu/linux-realtime<6.17.0-1010.11
6.17.0-1010.11
ubuntu/linux-riscv<6.17.0-22.22.1
6.17.0-22.22.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1
  2. Upgrade

    Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.55~22.04.1
  3. Upgrade

    Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1059.65~22.04.1
  4. Upgrade

    Upgrade ubuntu/linux-azure-fde-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1058.65~22.04.1
  5. Upgrade

    Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1054.57~22.04.1
  6. Upgrade

    Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-110.110~22.04.1
  7. Upgrade

    Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1051.51~22.04.1
  8. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-110.110.1~22.04.1
  9. Upgrade

    Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1051.54~22.04.1
  10. Upgrade

    Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1049.50~22.04.1
  11. Upgrade

    Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-110.110~22.04.1
  12. Upgrade

    Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.1-1047.48~22.04.1
  13. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 6.8.0-110.110
  14. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.55
  15. Upgrade

    Upgrade ubuntu/linux-aws-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1012.12~24.04.1
  16. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 6.8.0-1054.60
  17. Upgrade

    Upgrade ubuntu/linux-azure-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1013.13~24.04.1
  18. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 6.8.0-1058.65
  19. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 6.8.0-1054.57
  20. Upgrade

    Upgrade ubuntu/linux-gcp-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1012.12~24.04.1
  21. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 6.8.0-1050.56
  22. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 6.8.0-1037.40
  23. Upgrade

    Upgrade ubuntu/linux-hwe-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-22.22~24.04.1
  24. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 6.8.0-1051.51
  25. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-110.110.1
  26. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 6.8.0-1051.54
  27. Upgrade

    Upgrade ubuntu/linux-nvidia-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1018.18
  28. Upgrade

    Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-1051.54.1
  29. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.

    Fixed in 6.8.0-1022.22
  30. Upgrade

    Upgrade ubuntu/linux-oem-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1020.20
  31. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 6.8.0-1049.50
  32. Upgrade

    Upgrade ubuntu/linux-oracle-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1011.11~24.04.1
  33. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.56
  34. Upgrade

    Upgrade ubuntu/linux-riscv-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-22.22.1~24.04.1
  35. Upgrade

    Upgrade ubuntu/linux-xilinx to a version that resolves this vulnerability.

    Fixed in 6.8.0-1028.29
  36. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 6.8.0-1017.21
  37. Upgrade

    Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.0-2042.43
  38. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.1-1047.48
  39. Upgrade

    Upgrade ubuntu/linux-realtime-6.17 to a version that resolves this vulnerability.

    Fixed in 6.17.0-1010.11~24.04.1
  40. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1052.55+fips1
  41. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1053.59+fips1
  42. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-110.110+fips2
  43. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1054.57+fips1
  44. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 6.17.0-22.22
  45. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 6.17.0-1012.12
  46. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 6.17.0-1013.13
  47. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 6.17.0-1012.12
  48. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 6.17.0-1011.11
  49. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 6.17.0-1013.13
  50. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 6.17.0-1010.11
  51. Upgrade

    Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.

    Fixed in 6.17.0-22.22.1

Event History

Jan 13, 2026
CVE Published
via MITRE·03:28 PM
Data Sourced
via MITRE·03:28 PM
DescriptionSeverity
Data Sourced
via OSV·04:15 PM
DescriptionSeverityAffected Software
Event
via OSV·04:15 PM
Data Sourced
via NVD·04:15 PM
DescriptionSeverityWeakness
Jan 15, 2026
Data Sourced
via Microsoft·09:06 AM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

What is the severity of CVE-2025-68775?

CVE-2025-68775 has a medium severity rating due to potential information leakage from duplicate handshake cancellations.

2

What systems are affected by CVE-2025-68775?

CVE-2025-68775 affects the Linux kernel networking subsystem.

3

How do I fix CVE-2025-68775?

To fix CVE-2025-68775, update your Linux kernel to the latest stable version that includes the patch.

4

What impact does CVE-2025-68775 have on system security?

CVE-2025-68775 may allow attackers to leak sensitive information through improper handling of handshake cancellations.

5

When was CVE-2025-68775 discovered?

CVE-2025-68775 was identified and reported in 2025.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203