CVE-2025-40079: riscv, bpf: Sign extend struct ops return values properly

Published Oct 28, 2025
·
Updated

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

riscv, bpf: Sign extend struct ops return values properly

The nsbpfqdisc selftest triggers a kernel panic:

Unable to handle kernel paging request at virtual address ffffffffa38dbf58 Current testprogs pgtable: 4K pagesize, 57-bit VAs, pgdp=0x00000001109cc000 [ffffffffa38dbf58] pgd=000000011fffd801, p4d=000000011fffd401, pud=000000011fffd001, pmd=0000000000000000 Oops [#1] Modules linked in: bpftestmod(OE) xtconntrack nlsiso88591 [...] [last unloaded: bpftestmod(OE)] CPU: 1 UID: 0 PID: 23584 Comm: testprogs Tainted: G W OE 6.17.0-rc1-g2465bb83e0b4 #1 NONE Tainted: [W]=WARN, [O]=OOTMODULE, [E]=UNSIGNEDMODULE Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2024.01+dfsg-1ubuntu5.1 01/01/2024 epc : qdiscrun+0x82/0x6f0 ra : qdiscrun+0x6e/0x6f0 epc : ffffffff80bd5c7a ra : ffffffff80bd5c66 sp : ff2000000eecb550 gp : ffffffff82472098 tp : ff60000096895940 t0 : ffffffff8001f180 t1 : ffffffff801e1664 t2 : 0000000000000000 s0 : ff2000000eecb5d0 s1 : ff60000093a6a600 a0 : ffffffffa38dbee8 a1 : 0000000000000001 a2 : ff2000000eecb510 a3 : 0000000000000001 a4 : 0000000000000000 a5 : 0000000000000010 a6 : 0000000000000000 a7 : 0000000000735049 s2 : ffffffffa38dbee8 s3 : 0000000000000040 s4 : ff6000008bcda000 s5 : 0000000000000008 s6 : ff60000093a6a680 s7 : ff60000093a6a6f0 s8 : ff60000093a6a6ac s9 : ff60000093140000 s10: 0000000000000000 s11: ff2000000eecb9d0 t3 : 0000000000000000 t4 : 0000000000ff0000 t5 : 0000000000000000 t6 : ff60000093a6a8b6 status: 0000000200000120 badaddr: ffffffffa38dbf58 cause: 000000000000000d [<ffffffff80bd5c7a>] qdiscrun+0x82/0x6f0 [<ffffffff80b6fe58>] devqueuexmit+0x4c0/0x1128 [<ffffffff80b80ae0>] neighresolveoutput+0xd0/0x170 [<ffffffff80d2daf6>] ip6finishoutput2+0x226/0x6c8 [<ffffffff80d31254>] ip6finishoutput+0x10c/0x2a0 [<ffffffff80d31446>] ip6output+0x5e/0x178 [<ffffffff80d2e232>] ip6xmit+0x29a/0x608 [<ffffffff80d6f4c6>] inet6cskxmit+0xe6/0x140 [<ffffffff80c985e4>] tcptransmitskb+0x45c/0xaa8 [<ffffffff80c995fe>] tcpconnect+0x9ce/0xd10 [<ffffffff80d66524>] tcpv6connect+0x4ac/0x5e8 [<ffffffff80cc19b8>] inetstreamconnect+0xd8/0x318 [<ffffffff80cc1c36>] inetstreamconnect+0x3e/0x68 [<ffffffff80b42b20>] sysconnectfile+0x50/0x88 [<ffffffff80b42bee>] sysconnect+0x96/0xc8 [<ffffffff80b42c40>] riscvsysconnect+0x20/0x30 [<ffffffff80e5bcae>] dotrapecallu+0x256/0x378 [<ffffffff80e69af2>] handleexception+0x14a/0x156 Code: 892a 0363 1205 489c 8bc1 c7e5 2d03 084a 2703 080a (2783) 0709 ---[ end trace 0000000000000000 ]---

The bpffifodequeue prog returns a skb which is a pointer. The pointer is treated as a 32bit value and sign extend to 64bit in epilogue. This behavior is right for most bpf prog types but wrong for struct ops which requires RISC-V ABI.

So let's sign extend struct ops return values according to the function model and RISC-V ABI([0]).

[0]: https://riscv.org/wp-content/uploads/2024/12/riscv-calling.pdf

Affected Software

149 affected componentsFixes available
Linux Linux kernel
Microsoft azl3 kernel 6.6.104.2-4
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

Oct 28, 2025
CVE Published
via MITRE·11:48 AM
Data Sourced
via MITRE·11:48 AM
DescriptionSeverity
Data Sourced
via OSV·12:15 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·12:15 PM
DescriptionSeverity
Oct 29, 2025
Data Sourced
via Microsoft·01:05 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·01:05 AM
Affected Software

Frequently Asked Questions

1

What is the severity of CVE-2025-40079?

CVE-2025-40079 is categorized as a high-severity vulnerability due to its potential to trigger a kernel panic.

2

How do I fix CVE-2025-40079?

To resolve CVE-2025-40079, it is recommended to update your Linux kernel to the latest version provided by your distribution.

3

What software is affected by CVE-2025-40079?

CVE-2025-40079 affects the Linux kernel, specifically impacting systems utilizing the riscv and bpf components.

4

What impact does CVE-2025-40079 have on my system?

The impact of CVE-2025-40079 includes the risk of kernel panics, leading to system instability and potential downtime.

5

Has CVE-2025-40079 been patched?

Yes, CVE-2025-40079 has been patched in subsequent updates to the Linux kernel, addressing the identified issues.

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