CVE-2025-21725: smb: client: fix oops due to unset link speed

Published Feb 27, 2025
·
Updated

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

smb: client: fix oops due to unset link speed

It isn't guaranteed that NETWORKINTERFACEINFO::LinkSpeed will always be set by the server, so the client must handle any values and then prevent oopses like below from happening:

Oops: divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 UID: 0 PID: 1323 Comm: cat Not tainted 6.13.0-rc7 #2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-3.fc41 04/01/2014 RIP: 0010:cifsdebugdataprocshow+0xa45/0x1460 [cifs] Code: 00 00 48 89 df e8 3b cd 1b c1 41 f6 44 24 2c 04 0f 84 50 01 00 00 48 89 ef e8 e7 d0 1b c1 49 8b 44 24 18 31 d2 49 8d 7c 24 28 <48> f7 74 24 18 48 89 c3 e8 6e cf 1b c1 41 8b 6c 24 28 49 8d 7c 24 RSP: 0018:ffffc90001817be0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88811230022c RCX: ffffffffc041bd99 RDX: 0000000000000000 RSI: 0000000000000567 RDI: ffff888112300228 RBP: ffff888112300218 R08: fffff52000302f5f R09: ffffed1022fa58ac R10: ffff888117d2c566 R11: 00000000fffffffe R12: ffff888112300200 R13: 000000012a15343f R14: 0000000000000001 R15: ffff888113f2db58 FS: 00007fe27119e740(0000) GS:ffff888148600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe2633c5000 CR3: 0000000124da0000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? diebody.cold+0x19/0x27 ? die+0x2e/0x50 ? dotrap+0x159/0x1b0 ? cifsdebugdataprocshow+0xa45/0x1460 [cifs] ? doerrortrap+0x90/0x130 ? cifsdebugdataprocshow+0xa45/0x1460 [cifs] ? excdivideerror+0x39/0x50 ? cifsdebugdataprocshow+0xa45/0x1460 [cifs] ? asmexcdivideerror+0x1a/0x20 ? cifsdebugdataprocshow+0xa39/0x1460 [cifs] ? cifsdebugdataprocshow+0xa45/0x1460 [cifs] ? seqreaditer+0x42e/0x790 seqreaditer+0x19a/0x790 procregreaditer+0xbe/0x110 ? pfxprocregreaditer+0x10/0x10 vfsread+0x469/0x570 ? douseraddrfault+0x398/0x760 ? pfxvfsread+0x10/0x10 ? findheldlock+0x8a/0xa0 ? pfxlockrelease+0x10/0x10 ksysread+0xd3/0x170 ? pfxksysread+0x10/0x10 ? rcureadunlock+0x50/0x270 ? markheldlocks+0x1a/0x90 dosyscall64+0xbb/0x1d0 entrySYSCALL64afterhwframe+0x77/0x7f RIP: 0033:0x7fe271288911 Code: 00 48 8b 15 01 25 10 00 f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 20 ad 01 00 f3 0f 1e fa 80 3d b5 a7 10 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 4f c3 66 0f 1f 44 00 00 55 48 89 e5 48 83 ec RSP: 002b:00007ffe87c079d8 EFLAGS: 00000246 ORIGRAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007fe271288911 RDX: 0000000000040000 RSI: 00007fe2633c6000 RDI: 0000000000000003 RBP: 00007ffe87c07a00 R08: 0000000000000000 R09: 00007fe2713e6380 R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000040000 R13: 00007fe2633c6000 R14: 0000000000000003 R15: 0000000000000000 </TASK>

Fix this by setting cifsserveriface::speed to a sane value (1Gbps) by default when link speed is unset.

Affected Software

126 affected componentsFixes available
Linux Linux kernel
Linux Linux kernel>=6.1.65<6.1.129
Linux Linux kernel>=6.6.4<6.6.76
Linux Linux kernel>=6.7<6.12.13
Linux Linux kernel>=6.13<6.13.2
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*
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15*
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<6.8.0-1032.34~22.04.1
6.8.0-1032.34~22.04.1
ubuntu/linux-azure*
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8<6.8.0-1034.39~22.04.1
6.8.0-1034.39~22.04.1
ubuntu/linux-azure-fde*
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<6.8.0-1033.35~22.04.1
6.8.0-1033.35~22.04.1
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-hwe-6.8<6.8.0-64.67~22.04.1
6.8.0-64.67~22.04.1
ubuntu/linux-ibm-6.8<6.8.0-1029.29~22.04.1
6.8.0-1029.29~22.04.1
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<6.8.0-64.67.1~22.04.1
6.8.0-64.67.1~22.04.1
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8<6.8.0-1031.34~22.04.1
6.8.0-1031.34~22.04.1
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<6.8.0-1029.30~22.04.1
6.8.0-1029.30~22.04.1
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8<6.8.0-64.67~22.04.1
6.8.0-64.67~22.04.1
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-realtime-6.8<6.8.1-1025.26~22.04.1
6.8.1-1025.26~22.04.1
ubuntu/linux-azure-fips*
ubuntu/linux<6.8.0-64.67
6.8.0-64.67
ubuntu/linux-aws<6.8.0-1032.34
6.8.0-1032.34
ubuntu/linux-azure<6.8.0-1034.39
6.8.0-1034.39
ubuntu/linux-azure-6.11<6.11.0-1015.15~24.04.1
6.11.0-1015.15~24.04.1
ubuntu/linux-azure-nvidia<6.8.0-1022.23
6.8.0-1022.23
ubuntu/linux-gcp<6.8.0-1033.35
6.8.0-1033.35
ubuntu/linux-gcp-6.11<6.11.0-1015.15~24.04.1
6.11.0-1015.15~24.04.1
ubuntu/linux-gke<6.8.0-1028.32
6.8.0-1028.32
ubuntu/linux-gkeop<6.8.0-1015.17
6.8.0-1015.17
ubuntu/linux-hwe-6.11<6.11.0-26.26~24.04.1
6.11.0-26.26~24.04.1
ubuntu/linux-ibm<6.8.0-1029.29
6.8.0-1029.29
ubuntu/linux-lowlatency<6.8.0-64.67.1
6.8.0-64.67.1
ubuntu/linux-lowlatency-hwe-6.11<6.11.0-1014.15~24.04.1
6.11.0-1014.15~24.04.1
ubuntu/linux-nvidia<6.8.0-1031.34
6.8.0-1031.34
ubuntu/linux-nvidia-6.11<6.11.0-1010.10
6.11.0-1010.10
ubuntu/linux-nvidia-lowlatency<6.8.0-1031.34.1
6.8.0-1031.34.1
ubuntu/linux-nvidia-tegra<6.8.0-1008.8
6.8.0-1008.8
ubuntu/linux-oem-6.11<6.11.0-1022.22
6.11.0-1022.22
ubuntu/linux-oem-6.8<6.8.0-1031.31
6.8.0-1031.31
ubuntu/linux-oracle<6.8.0-1029.30
6.8.0-1029.30
ubuntu/linux-raspi<6.8.0-1031.35
6.8.0-1031.35
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-xilinx<6.8.0-1017.18
6.8.0-1017.18
ubuntu/linux-raspi-realtime<6.8.0-2026.27
6.8.0-2026.27
ubuntu/linux-realtime<6.8.1-1025.26
6.8.1-1025.26
ubuntu/linux-fips<6.8.0-78.78+fips1
6.8.0-78.78+fips1
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 6.8.0-1032.34~22.04.1
  2. Upgrade

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

    Fixed in 6.8.0-1034.39~22.04.1
  3. Upgrade

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

    Fixed in 6.8.0-1033.35~22.04.1
  4. Upgrade

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

    Fixed in 6.8.0-64.67~22.04.1
  5. Upgrade

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

    Fixed in 6.8.0-1029.29~22.04.1
  6. Upgrade

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

    Fixed in 6.8.0-64.67.1~22.04.1
  7. Upgrade

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

    Fixed in 6.8.0-1031.34~22.04.1
  8. Upgrade

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

    Fixed in 6.8.0-1029.30~22.04.1
  9. Upgrade

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

    Fixed in 6.8.0-64.67~22.04.1
  10. Upgrade

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

    Fixed in 6.8.1-1025.26~22.04.1
  11. Upgrade

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

    Fixed in 6.8.0-64.67
  12. Upgrade

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

    Fixed in 6.8.0-1032.34
  13. Upgrade

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

    Fixed in 6.8.0-1034.39
  14. Upgrade

    Upgrade ubuntu/linux-azure-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-1015.15~24.04.1
  15. Upgrade

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

    Fixed in 6.8.0-1022.23
  16. Upgrade

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

    Fixed in 6.8.0-1033.35
  17. Upgrade

    Upgrade ubuntu/linux-gcp-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-1015.15~24.04.1
  18. Upgrade

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

    Fixed in 6.8.0-1028.32
  19. Upgrade

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

    Fixed in 6.8.0-1015.17
  20. Upgrade

    Upgrade ubuntu/linux-hwe-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-26.26~24.04.1
  21. Upgrade

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

    Fixed in 6.8.0-1029.29
  22. Upgrade

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

    Fixed in 6.8.0-64.67.1
  23. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-1014.15~24.04.1
  24. Upgrade

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

    Fixed in 6.8.0-1031.34
  25. Upgrade

    Upgrade ubuntu/linux-nvidia-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-1010.10
  26. Upgrade

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

    Fixed in 6.8.0-1031.34.1
  27. Upgrade

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

    Fixed in 6.8.0-1008.8
  28. Upgrade

    Upgrade ubuntu/linux-oem-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-1022.22
  29. Upgrade

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

    Fixed in 6.8.0-1031.31
  30. Upgrade

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

    Fixed in 6.8.0-1029.30
  31. Upgrade

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

    Fixed in 6.8.0-1031.35
  32. Upgrade

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

    Fixed in 6.8.0-1017.18
  33. Upgrade

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

    Fixed in 6.8.0-2026.27
  34. Upgrade

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

    Fixed in 6.8.1-1025.26
  35. Upgrade

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

    Fixed in 6.8.0-78.78+fips1
  36. Configuration

    Set cifs_server_iface::speed to 1Gbps by default when NETWORK_INTERFACE_INFO::LinkSpeed is unset.

    Linux kernel SMB client cifs_server_iface::speed = 1Gbps

Event History

Feb 27, 2025
CVE Published
via MITRE·02:07 AM
Data Sourced
via MITRE·02:07 AM
DescriptionSeverity
Data Sourced
via OSV·02:15 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·02:15 AM
RemedyDescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2025-21725?

CVE-2025-21725 has a medium severity rating due to the potential for client-side crashes in Linux kernel networking.

2

How do I fix CVE-2025-21725?

To fix CVE-2025-21725, upgrade to a patched version of the Linux kernel that addresses this vulnerability.

3

What systems are affected by CVE-2025-21725?

CVE-2025-21725 affects various versions of the Linux kernel, specifically versions between 6.1.65 to 6.1.129, 6.6.4 to 6.6.76, 6.7 to 6.12.13, and 6.13 to 6.13.2.

4

What does the CVE-2025-21725 vulnerability involve?

CVE-2025-21725 involves an issue where the Linux kernel's SMB client handles unset link speed, which can lead to system crashes.

5

Are there any workarounds for CVE-2025-21725?

There are no widely recommended workarounds for CVE-2025-21725 other than applying the recommended patches promptly.

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