CVE-2025-37954: smb: client: Avoid race in open_cached_dir with lease breaks

Published May 20, 2025
·
Updated

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

smb: client: Avoid race in opencacheddir with lease breaks

A pre-existing valid cfid returned from findorcreatecacheddir might race with a lease break, meaning opencacheddir doesn't consider it valid, and thinks it's newly-constructed. This leaks a dentry reference if the allocation occurs before the queued lease break work runs.

Avoid the race by extending holding the cfidlistlock across findorcreatecacheddir and when the result is checked.

Affected Software

142 affected componentsFixes available
Linux Kernel
Microsoft azl3 kernel 6.6.85.1-4
Patch available
Linux Linux kernel<6.6.91
Linux Linux kernel>=6.7<6.12.29
Linux Linux kernel>=6.13<6.14.7
Linux Linux kernel=6.15-rc1
Linux Linux kernel=6.15-rc2
Linux Linux kernel=6.15-rc3
Linux Linux kernel=6.15-rc4
Linux Linux kernel=6.15-rc5
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-5.15<5.15.0-1096.105~20.04.1
5.15.0-1096.105~20.04.1
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<6.8.0-1046.49~22.04.1
6.8.0-1046.49~22.04.1
ubuntu/linux-azure<5.15.0-1096.105
5.15.0-1096.105
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8<6.8.0-1036.42~22.04.1
6.8.0-1036.42~22.04.1
ubuntu/linux-azure-fde<5.15.0-1096.105.1
5.15.0-1096.105.1
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8<6.8.0-1047.50~22.04.2
6.8.0-1047.50~22.04.2
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-hwe-6.8<6.8.0-100.100~22.04.1
6.8.0-100.100~22.04.1
ubuntu/linux-ibm-6.8<6.8.0-1044.44~22.04.1
6.8.0-1044.44~22.04.1
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<6.8.0-100.100.1~22.04.1
6.8.0-100.100.1~22.04.1
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8<6.8.0-1046.49~22.04.1
6.8.0-1046.49~22.04.1
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<6.8.0-1043.44~22.04.1
6.8.0-1043.44~22.04.1
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8<6.8.0-100.100~22.04.1
6.8.0-100.100~22.04.1
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-realtime-6.8<6.8.1-1041.42~22.04.1
6.8.1-1041.42~22.04.1
ubuntu/linux-azure-fips<5.15.0-1096.105+fips1
5.15.0-1096.105+fips1
ubuntu/linux<6.8.0-100.100
6.8.0-100.100
ubuntu/linux-aws<6.8.0-1046.49
6.8.0-1046.49
ubuntu/linux-aws-6.14<6.14.0-1011.11~24.04.1
6.14.0-1011.11~24.04.1
ubuntu/linux-azure<6.8.0-1038.44
6.8.0-1038.44
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-nvidia<6.8.0-1025.27
6.8.0-1025.27
ubuntu/linux-gcp<6.8.0-1047.50
6.8.0-1047.50
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14<6.14.0-1014.15~24.04.1
6.14.0-1014.15~24.04.1
ubuntu/linux-gke<6.8.0-1043.48
6.8.0-1043.48
ubuntu/linux-gkeop<6.8.0-1030.33
6.8.0-1030.33
ubuntu/linux-hwe-6.11*
ubuntu/linux-ibm<6.8.0-1044.44
6.8.0-1044.44
ubuntu/linux-intel*
ubuntu/linux-lowlatency<6.8.0-100.100.1
6.8.0-100.100.1
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia<6.8.0-1046.49
6.8.0-1046.49
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-lowlatency<6.8.0-1046.49.1
6.8.0-1046.49.1
ubuntu/linux-nvidia-tegra<6.8.0-1020.20
6.8.0-1020.20
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14<6.14.0-1010.10
6.14.0-1010.10
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle<6.8.0-1043.44
6.8.0-1043.44
ubuntu/linux-oracle-6.14<6.14.0-1011.11~24.04.1
6.14.0-1011.11~24.04.1
ubuntu/linux-raspi<6.8.0-1047.51
6.8.0-1047.51
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14<6.14.0-28.28.1~24.04.1
6.14.0-28.28.1~24.04.1
ubuntu/linux-xilinx<6.8.0-1023.24
6.8.0-1023.24
ubuntu/linux-bluefield<6.8.0-1016.20
6.8.0-1016.20
ubuntu/linux-raspi-realtime<6.8.0-2037.38
6.8.0-2037.38
ubuntu/linux-realtime<6.8.1-1041.42
6.8.1-1041.42
ubuntu/linux-realtime-6.14<6.14.0-1010.10~24.04.1
6.14.0-1010.10~24.04.1
ubuntu/linux-aws-fips<6.8.0-1046.49+fips1
6.8.0-1046.49+fips1
ubuntu/linux-azure-fips<6.8.0-1040.46+fips1
6.8.0-1040.46+fips1
ubuntu/linux-fips<6.8.0-100.100+fips1
6.8.0-100.100+fips1
ubuntu/linux-gcp-fips<6.8.0-1047.50+fips1
6.8.0-1047.50+fips1
ubuntu/linux-azure-fde*
ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1096.105~20.04.1
  2. Upgrade

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

    Fixed in 6.8.0-1046.49~22.04.1
  3. Upgrade

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

    Fixed in 5.15.0-1096.105
  4. Upgrade

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

    Fixed in 6.8.0-1036.42~22.04.1
  5. Upgrade

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

    Fixed in 5.15.0-1096.105.1
  6. Upgrade

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

    Fixed in 6.8.0-1047.50~22.04.2
  7. Upgrade

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

    Fixed in 6.8.0-100.100~22.04.1
  8. Upgrade

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

    Fixed in 6.8.0-1044.44~22.04.1
  9. Upgrade

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

    Fixed in 6.8.0-100.100.1~22.04.1
  10. Upgrade

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

    Fixed in 6.8.0-1046.49~22.04.1
  11. Upgrade

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

    Fixed in 6.8.0-1043.44~22.04.1
  12. Upgrade

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

    Fixed in 6.8.0-100.100~22.04.1
  13. Upgrade

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

    Fixed in 6.8.1-1041.42~22.04.1
  14. Upgrade

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

    Fixed in 5.15.0-1096.105+fips1
  15. Upgrade

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

    Fixed in 6.8.0-100.100
  16. Upgrade

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

    Fixed in 6.8.0-1046.49
  17. Upgrade

    Upgrade ubuntu/linux-aws-6.14 to a version that resolves this vulnerability.

    Fixed in 6.14.0-1011.11~24.04.1
  18. Upgrade

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

    Fixed in 6.8.0-1038.44
  19. Upgrade

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

    Fixed in 6.8.0-1025.27
  20. Upgrade

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

    Fixed in 6.8.0-1047.50
  21. Upgrade

    Upgrade ubuntu/linux-gcp-6.14 to a version that resolves this vulnerability.

    Fixed in 6.14.0-1014.15~24.04.1
  22. Upgrade

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

    Fixed in 6.8.0-1043.48
  23. Upgrade

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

    Fixed in 6.8.0-1030.33
  24. Upgrade

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

    Fixed in 6.8.0-1044.44
  25. Upgrade

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

    Fixed in 6.8.0-100.100.1
  26. Upgrade

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

    Fixed in 6.8.0-1046.49
  27. Upgrade

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

    Fixed in 6.8.0-1046.49.1
  28. Upgrade

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

    Fixed in 6.8.0-1020.20
  29. Upgrade

    Upgrade ubuntu/linux-oem-6.14 to a version that resolves this vulnerability.

    Fixed in 6.14.0-1010.10
  30. Upgrade

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

    Fixed in 6.8.0-1043.44
  31. Upgrade

    Upgrade ubuntu/linux-oracle-6.14 to a version that resolves this vulnerability.

    Fixed in 6.14.0-1011.11~24.04.1
  32. Upgrade

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

    Fixed in 6.8.0-1047.51
  33. Upgrade

    Upgrade ubuntu/linux-riscv-6.14 to a version that resolves this vulnerability.

    Fixed in 6.14.0-28.28.1~24.04.1
  34. Upgrade

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

    Fixed in 6.8.0-1023.24
  35. Upgrade

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

    Fixed in 6.8.0-1016.20
  36. Upgrade

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

    Fixed in 6.8.0-2037.38
  37. Upgrade

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

    Fixed in 6.8.1-1041.42
  38. Upgrade

    Upgrade ubuntu/linux-realtime-6.14 to a version that resolves this vulnerability.

    Fixed in 6.14.0-1010.10~24.04.1
  39. Upgrade

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

    Fixed in 6.8.0-1046.49+fips1
  40. Upgrade

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

    Fixed in 6.8.0-1040.46+fips1
  41. Upgrade

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

    Fixed in 6.8.0-100.100+fips1
  42. Upgrade

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

    Fixed in 6.8.0-1047.50+fips1
  43. Compensating control

    In the SMB client, hold cfid_list_lock across find_or_create_cached_dir and the subsequent result-validity check to avoid the race with lease breaks.

Event History

May 20, 2025
CVE Published
via MITRE·04:01 PM
Data Sourced
via MITRE·04:01 PM
DescriptionSeverity
Data Sourced
via OSV·04:15 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·04:15 PM
RemedyDescriptionSeverityAffected Software
Jul 11, 2025
Data Sourced
via Microsoft·12:00 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·12:00 AM
Affected Software

Frequently Asked Questions

1

What is the severity of CVE-2025-37954?

CVE-2025-37954 has not been assigned a severity rating as it is a recent vulnerability in the Linux kernel.

2

How do I fix CVE-2025-37954?

To fix CVE-2025-37954, update your Linux kernel to the latest version that addresses this vulnerability.

3

What type of vulnerability is CVE-2025-37954?

CVE-2025-37954 is a race condition vulnerability in the Linux kernel's SMB client component.

4

What systems are affected by CVE-2025-37954?

CVE-2025-37954 affects systems running the Linux kernel that utilizes the SMB client for file sharing.

5

Is there any known exploitation of CVE-2025-37954?

As of now, there have been no reported cases of exploitation of CVE-2025-37954 in the wild.

Company

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