CVE-2025-40320: smb: client: fix potential cfid UAF in smb2_query_info_compound

Published Dec 8, 2025
·
Updated

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

smb: client: fix potential cfid UAF in smb2queryinfocompound

When smb2queryinfocompound() retries, a previously allocated cfid may have been freed in the first attempt. Because cfid wasn't reset on replay, later cleanup could act on a stale pointer, leading to a potential use-after-free.

Reinitialize cfid to NULL under the replay label.

Example trace (trimmed):

refcountt: underflow; use-after-free. WARNING: CPU: 1 PID: 11224 at ../lib/refcount.c:28 refcountwarnsaturate+0x9c/0x110 [...] RIP: 0010:refcountwarnsaturate+0x9c/0x110 [...] Call Trace: <TASK> smb2queryinfocompound+0x29c/0x5c0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] ? stepinto+0x10d/0x690 ? legitimizepath+0x28/0x60 smb2queryfs+0x6a/0xf0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] smb311queryfs+0x12d/0x140 [cifs f90b72658819bd21c94769b6a652029a07a7172f] ? kmemcachealloc+0x18a/0x340 ? getnameflags+0x46/0x1e0 cifsstatfs+0x9f/0x2b0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] statfsbydentry+0x67/0x90 vfsstatfs+0x16/0xd0 userstatfs+0x54/0xa0 dosysstatfs+0x20/0x50 dosyscall64+0x58/0x80

Affected Software

148 affected componentsFixes available
Linux Linux kernel (cifs)
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<6.8.0-1050.53~22.04.1
6.8.0-1050.53~22.04.1
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8<6.8.0-1051.57~22.04.1
6.8.0-1051.57~22.04.1
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<6.8.0-1052.55~22.04.1
6.8.0-1052.55~22.04.1
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-hwe-6.8<6.8.0-106.106~22.04.1
6.8.0-106.106~22.04.1
ubuntu/linux-ibm-6.8<6.8.0-1049.49~22.04.1
6.8.0-1049.49~22.04.1
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<6.8.0-106.106.1~22.04.1
6.8.0-106.106.1~22.04.1
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8<6.8.0-1049.52~22.04.1
6.8.0-1049.52~22.04.1
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<6.8.0-1047.48~22.04.1
6.8.0-1047.48~22.04.1
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8<6.8.0-106.106~22.04.1
6.8.0-106.106~22.04.1
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-realtime-6.8<6.8.1-1045.46~22.04.1
6.8.1-1045.46~22.04.1
ubuntu/linux<6.8.0-106.106
6.8.0-106.106
ubuntu/linux-aws<6.8.0-1050.53
6.8.0-1050.53
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17<6.17.0-1007.7~24.04.1
6.17.0-1007.7~24.04.1
ubuntu/linux-azure<6.8.0-1051.57
6.8.0-1051.57
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-fde<6.8.0-1058.65
6.8.0-1058.65
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-nvidia<6.8.0-1039.42
6.8.0-1039.42
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp<6.8.0-1052.55
6.8.0-1052.55
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-6.17<6.17.0-1008.8~24.04.1
6.17.0-1008.8~24.04.1
ubuntu/linux-gke<6.8.0-1048.53
6.8.0-1048.53
ubuntu/linux-gkeop<6.8.0-1035.38
6.8.0-1035.38
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-ibm<6.8.0-1049.49
6.8.0-1049.49
ubuntu/linux-lowlatency<6.8.0-106.106.1
6.8.0-106.106.1
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia<6.8.0-1049.52
6.8.0-1049.52
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17<6.17.0-1008.8
6.17.0-1008.8
ubuntu/linux-nvidia-lowlatency<6.8.0-1049.52.1
6.8.0-1049.52.1
ubuntu/linux-nvidia-tegra<6.8.0-1020.20
6.8.0-1020.20
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17<6.17.0-1011.11
6.17.0-1011.11
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle<6.8.0-1047.48
6.8.0-1047.48
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17<6.17.0-1007.7~24.04.1
6.17.0-1007.7~24.04.1
ubuntu/linux-raspi<6.8.0-1050.54
6.8.0-1050.54
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
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<6.8.0-2040.41
6.8.0-2040.41
ubuntu/linux-realtime<6.8.1-1045.46
6.8.1-1045.46
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17<6.17.0-1006.7~24.04.1
6.17.0-1006.7~24.04.1
ubuntu/linux-aws-fips<6.8.0-1050.53+fips1
6.8.0-1050.53+fips1
ubuntu/linux-azure-fips<6.8.0-1052.58+fips1
6.8.0-1052.58+fips1
ubuntu/linux-fips<6.8.0-106.106+fips1
6.8.0-106.106+fips1
ubuntu/linux-gcp-fips<6.8.0-1052.55+fips1
6.8.0-1052.55+fips1
ubuntu/linux<6.17.0-14.14
6.17.0-14.14
ubuntu/linux-aws<6.17.0-1007.7
6.17.0-1007.7
ubuntu/linux-azure<6.17.0-1008.8
6.17.0-1008.8
ubuntu/linux-azure-fde*
ubuntu/linux-gcp<6.17.0-1007.7
6.17.0-1007.7
ubuntu/linux-oracle<6.17.0-1007.7
6.17.0-1007.7
ubuntu/linux-raspi<6.17.0-1008.8
6.17.0-1008.8
ubuntu/linux-realtime<6.17.0-1006.7
6.17.0-1006.7
ubuntu/linux-riscv<6.17.0-14.14.1
6.17.0-14.14.1
ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

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

    Fixed in 6.8.0-1050.53~22.04.1
  2. Upgrade

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

    Fixed in 6.8.0-1051.57~22.04.1
  3. 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
  4. Upgrade

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

    Fixed in 6.8.0-1052.55~22.04.1
  5. Upgrade

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

    Fixed in 6.8.0-106.106~22.04.1
  6. Upgrade

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

    Fixed in 6.8.0-1049.49~22.04.1
  7. Upgrade

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

    Fixed in 6.8.0-106.106.1~22.04.1
  8. Upgrade

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

    Fixed in 6.8.0-1049.52~22.04.1
  9. Upgrade

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

    Fixed in 6.8.0-1047.48~22.04.1
  10. Upgrade

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

    Fixed in 6.8.0-106.106~22.04.1
  11. Upgrade

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

    Fixed in 6.8.1-1045.46~22.04.1
  12. Upgrade

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

    Fixed in 6.8.0-106.106
  13. Upgrade

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

    Fixed in 6.8.0-1050.53
  14. Upgrade

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

    Fixed in 6.17.0-1007.7~24.04.1
  15. Upgrade

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

    Fixed in 6.8.0-1051.57
  16. Upgrade

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

    Fixed in 6.8.0-1058.65
  17. Upgrade

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

    Fixed in 6.8.0-1039.42
  18. Upgrade

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

    Fixed in 6.8.0-1052.55
  19. Upgrade

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

    Fixed in 6.17.0-1008.8~24.04.1
  20. Upgrade

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

    Fixed in 6.8.0-1048.53
  21. Upgrade

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

    Fixed in 6.8.0-1035.38
  22. Upgrade

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

    Fixed in 6.8.0-1049.49
  23. Upgrade

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

    Fixed in 6.8.0-106.106.1
  24. Upgrade

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

    Fixed in 6.8.0-1049.52
  25. Upgrade

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

    Fixed in 6.17.0-1008.8
  26. Upgrade

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

    Fixed in 6.8.0-1049.52.1
  27. Upgrade

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

    Fixed in 6.8.0-1020.20
  28. Upgrade

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

    Fixed in 6.17.0-1011.11
  29. Upgrade

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

    Fixed in 6.8.0-1047.48
  30. Upgrade

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

    Fixed in 6.17.0-1007.7~24.04.1
  31. Upgrade

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

    Fixed in 6.8.0-1050.54
  32. Upgrade

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

    Fixed in 6.8.0-1028.29
  33. Upgrade

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

    Fixed in 6.8.0-1017.21
  34. Upgrade

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

    Fixed in 6.8.0-2040.41
  35. Upgrade

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

    Fixed in 6.8.1-1045.46
  36. Upgrade

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

    Fixed in 6.17.0-1006.7~24.04.1
  37. Upgrade

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

    Fixed in 6.8.0-1050.53+fips1
  38. Upgrade

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

    Fixed in 6.8.0-1052.58+fips1
  39. Upgrade

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

    Fixed in 6.8.0-106.106+fips1
  40. Upgrade

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

    Fixed in 6.8.0-1052.55+fips1
  41. Upgrade

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

    Fixed in 6.17.0-14.14
  42. Upgrade

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

    Fixed in 6.17.0-1007.7
  43. Upgrade

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

    Fixed in 6.17.0-1008.8
  44. Upgrade

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

    Fixed in 6.17.0-1007.7
  45. Upgrade

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

    Fixed in 6.17.0-1007.7
  46. Upgrade

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

    Fixed in 6.17.0-1008.8
  47. Upgrade

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

    Fixed in 6.17.0-1006.7
  48. Upgrade

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

    Fixed in 6.17.0-14.14.1

Event History

Dec 8, 2025
CVE Published
via MITRE·12:46 AM
Data Sourced
via MITRE·12:46 AM
DescriptionSeverity
Data Sourced
via OSV·01:16 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·01:16 AM
DescriptionSeverity
Data Sourced
via Red Hat·07:10 AM
DescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2025-40320?

CVE-2025-40320 has been classified with a moderate severity level due to the potential for use-after-free vulnerabilities in the Linux kernel.

2

How do I fix CVE-2025-40320?

To fix CVE-2025-40320, update the Linux kernel to the latest patched version provided by your distribution.

3

What systems are affected by CVE-2025-40320?

CVE-2025-40320 affects the Linux Kernel, particularly instances using the SMB client.

4

What is the primary impact of CVE-2025-40320?

The primary impact of CVE-2025-40320 is the potential for remote code execution due to a use-after-free condition.

5

When was CVE-2025-40320 disclosed?

CVE-2025-40320 was disclosed as part of ongoing security updates to the Linux kernel.

Company

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