CVE-2026-98482: nfc: llcp: drop truncated I/RR/RNR PDUs in nfc_llcp_recv_hdlc()

Published Oct 18, 2026
·
Updated

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

nfc: llcp: drop truncated I/RR/RNR PDUs in nfcllcprecvhdlc()

nfcllcprecvhdlc() reads the sequence byte skb->data[2], via nfcllcpns()/nfcllcpnr(), before any length check. The receive path only guarantees the two-byte LLCP header -- nfcllcprecv() checks it with pskbmaypull() and nfcllcprecvagf() admits two-byte inner PDUs -- so a two-byte I, RR or RNR PDU reads one byte of uninitialised skb tailroom. The byte becomes N(R)/N(S); a peer can already set those with a well-formed PDU, so this is acting on uninitialised memory, not new peer control.

Guard the read with pskbmaypull(), as commit 95674f506c63 ("nfc: llcp: reject PDUs shorter than the LLCP header") did for the two-byte header, so the sequence byte is present and linear before it is read. RR and RNR PDUs are LLCPHEADERSIZE + LLCPSEQUENCESIZE bytes and an I PDU is longer, so no valid frame is rejected; a truncated PDU is malformed, so return without a DM reply.

Affected Software

264 affected componentsFixes available
Linux Linux kernel
Microsoft azl3 kernel 6.6.157.1-1<6.6.159.1-1
6.6.159.1-1
linux/kernel>=3.3.0<5.10.271
5.10.271
linux/kernel>=5.11.0<5.15.222
5.15.222
linux/kernel>=5.16.0<6.1.189
6.1.189
linux/kernel>=6.2.0<6.6.158
6.6.158
linux/kernel>=6.7.0<6.12.112
6.12.112
linux/kernel>=6.13.0<6.18.55
6.18.55
linux/kernel>=6.19.0<7.2.9
7.2.9
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-azure*
ubuntu/linux-lts-xenial*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-hwe*
ubuntu/linux-azure*
ubuntu/linux-gcp*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-kvm*
ubuntu/linux-oracle*
ubuntu/linux-fips*
ubuntu/linux-fips*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-aws-5.4*
ubuntu/linux-azure*
ubuntu/linux-azure-4.15*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-5.4*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-4.15*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gcp-5.4*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-5.4*
ubuntu/linux-hwe-edge*
ubuntu/linux-ibm-5.4*
ubuntu/linux-kvm*
ubuntu/linux-oem*
ubuntu/linux-oracle*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-oracle-5.4*
ubuntu/linux-raspi-5.4*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.15<5.15.0-1119.126~20.04.1
5.15.0-1119.126~20.04.1
ubuntu/linux-aws-5.8*
ubuntu/linux-azure*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.15<5.15.0-1125.134~20.04.1
5.15.0-1125.134~20.04.1
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15<5.15.0-1124.133~20.04.1
5.15.0-1124.133~20.04.1
ubuntu/linux-bluefield*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.15<5.15.0-1120.130~20.04.1
5.15.0-1120.130~20.04.1
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-5.15<5.15.0-202.212~20.04.1
5.15.0-202.212~20.04.1
ubuntu/linux-hwe-5.8*
ubuntu/linux-ibm*
ubuntu/linux-ibm-5.15<5.15.0-1113.117~20.04.1
5.15.0-1113.117~20.04.1
ubuntu/linux-intel-5.13*
ubuntu/linux-intel-iotg-5.15<5.15.0-1114.120~20.04.1
5.15.0-1114.120~20.04.1
ubuntu/linux-iot*
ubuntu/linux-kvm*
ubuntu/linux-lowlatency-hwe-5.15<5.15.0-197.207~20.04.1
5.15.0-197.207~20.04.1
ubuntu/linux-nvidia-tegra-5.15<5.15.0-1070.72~20.04.1
5.15.0-1070.72~20.04.1
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.15<5.15.0-1116.122~20.04.1
5.15.0-1116.122~20.04.1
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.15<5.15.0-1113.117~20.04.2
5.15.0-1113.117~20.04.2
ubuntu/linux-riscv-5.8*
ubuntu/linux-xilinx-zynqmp*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<5.15.0-202.212
5.15.0-202.212
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws<5.15.0-1119.126
5.15.0-1119.126
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8*
ubuntu/linux-azure<5.15.0-1125.134
5.15.0-1125.134
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8*
ubuntu/linux-azure-fde<5.15.0-1124.133
5.15.0-1124.133
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8*
ubuntu/linux-gcp<5.15.0-1120.130
5.15.0-1120.130
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8*
ubuntu/linux-gke<5.15.0-1115.121
5.15.0-1115.121
ubuntu/linux-gkeop<5.15.0-1102.110
5.15.0-1102.110
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-ibm<5.15.0-1113.117
5.15.0-1113.117
ubuntu/linux-ibm-6.8*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-intel-iotg<5.15.0-1114.120
5.15.0-1114.120
ubuntu/linux-kvm<5.15.0-1111.116
5.15.0-1111.116
ubuntu/linux-lowlatency<5.15.0-197.207
5.15.0-197.207
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8*
ubuntu/linux-nvidia<5.15.0-1114.115
5.15.0-1114.115
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8*
ubuntu/linux-nvidia-tegra<5.15.0-1070.72
5.15.0-1070.72
ubuntu/linux-nvidia-tegra-igx<5.15.0-1059.59
5.15.0-1059.59
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle<5.15.0-1116.122
5.15.0-1116.122
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8*
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8*
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-xilinx-zynqmp*
ubuntu/linux-bluefield<5.15.0-1103.105
5.15.0-1103.105
ubuntu/linux-intel-iot-realtime<5.15.0-1111.115
5.15.0-1111.115
ubuntu/linux-realtime<5.15.0-1118.127
5.15.0-1118.127
ubuntu/linux-realtime-6.8*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips<5.15.0-1119.126+fips1
5.15.0-1119.126+fips1
ubuntu/linux-azure-fips<5.15.0-1125.134+fips1
5.15.0-1125.134+fips1
ubuntu/linux-fips<5.15.0-202.212+fips1
5.15.0-202.212+fips1
ubuntu/linux-gcp-fips<5.15.0-1120.130+fips1
5.15.0-1120.130+fips1
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17*
ubuntu/linux-aws-7.0*
ubuntu/linux-azure*
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17*
ubuntu/linux-azure-7.0*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-fde-6.17*
ubuntu/linux-azure-fde-7.0*
ubuntu/linux-azure-nvidia*
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp*
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-7.0*
ubuntu/linux-gke*
ubuntu/linux-gkeop*
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17*
ubuntu/linux-hwe-7.0<7.0.0-42.42~24.04.1
7.0.0-42.42~24.04.1
ubuntu/linux-ibm*
ubuntu/linux-lowlatency*
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17*
ubuntu/linux-nvidia-7.0*
ubuntu/linux-nvidia-lowlatency*
ubuntu/linux-nvidia-tegra*
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17*
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle*
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17*
ubuntu/linux-oracle-7.0*
ubuntu/linux-raspi*
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17*
ubuntu/linux-riscv-7.0<7.0.0-42.42.1~24.04.1
7.0.0-42.42.1~24.04.1
ubuntu/linux-vmware*
ubuntu/linux-xilinx*
ubuntu/linux-bluefield*
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<7.0.0-42.42
7.0.0-42.42
ubuntu/linux-aws<7.0.0-1016.17
7.0.0-1016.17
ubuntu/linux-azure*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp<7.0.0-1016.18
7.0.0-1016.18
ubuntu/linux-gke*
ubuntu/linux-ibm<7.0.0-1017.17
7.0.0-1017.17
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-bos*
ubuntu/linux-oem-7.0<7.0.0-1017.17
7.0.0-1017.17
ubuntu/linux-oracle<7.0.0-1015.16
7.0.0-1015.16
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv<7.0.0-42.42.1
7.0.0-42.42.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.6.159.1-1
  2. Upgrade

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

    Fixed in 5.10.271
  3. Upgrade

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

    Fixed in 5.15.222
  4. Upgrade

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

    Fixed in 6.1.189
  5. Upgrade

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

    Fixed in 6.6.158
  6. Upgrade

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

    Fixed in 6.12.112
  7. Upgrade

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

    Fixed in 6.18.55
  8. Upgrade

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

    Fixed in 7.2.9
  9. Upgrade

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

    Fixed in 5.15.0-1119.126~20.04.1
  10. Upgrade

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

    Fixed in 5.15.0-1125.134~20.04.1
  11. Upgrade

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

    Fixed in 5.15.0-1124.133~20.04.1
  12. Upgrade

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

    Fixed in 5.15.0-1120.130~20.04.1
  13. Upgrade

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

    Fixed in 5.15.0-202.212~20.04.1
  14. Upgrade

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

    Fixed in 5.15.0-1113.117~20.04.1
  15. Upgrade

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

    Fixed in 5.15.0-1114.120~20.04.1
  16. Upgrade

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

    Fixed in 5.15.0-197.207~20.04.1
  17. Upgrade

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

    Fixed in 5.15.0-1070.72~20.04.1
  18. Upgrade

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

    Fixed in 5.15.0-1116.122~20.04.1
  19. Upgrade

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

    Fixed in 5.15.0-1113.117~20.04.2
  20. Upgrade

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

    Fixed in 5.15.0-202.212
  21. Upgrade

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

    Fixed in 5.15.0-1119.126
  22. Upgrade

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

    Fixed in 5.15.0-1125.134
  23. Upgrade

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

    Fixed in 5.15.0-1124.133
  24. Upgrade

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

    Fixed in 5.15.0-1120.130
  25. Upgrade

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

    Fixed in 5.15.0-1115.121
  26. Upgrade

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

    Fixed in 5.15.0-1102.110
  27. Upgrade

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

    Fixed in 5.15.0-1113.117
  28. Upgrade

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

    Fixed in 5.15.0-1114.120
  29. Upgrade

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

    Fixed in 5.15.0-1111.116
  30. Upgrade

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

    Fixed in 5.15.0-197.207
  31. Upgrade

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

    Fixed in 5.15.0-1114.115
  32. Upgrade

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

    Fixed in 5.15.0-1070.72
  33. Upgrade

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

    Fixed in 5.15.0-1059.59
  34. Upgrade

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

    Fixed in 5.15.0-1116.122
  35. Upgrade

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

    Fixed in 5.15.0-1103.105
  36. Upgrade

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

    Fixed in 5.15.0-1111.115
  37. Upgrade

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

    Fixed in 5.15.0-1118.127
  38. Upgrade

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

    Fixed in 5.15.0-1119.126+fips1
  39. Upgrade

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

    Fixed in 5.15.0-1125.134+fips1
  40. Upgrade

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

    Fixed in 5.15.0-202.212+fips1
  41. Upgrade

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

    Fixed in 5.15.0-1120.130+fips1
  42. Upgrade

    Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-42.42~24.04.1
  43. Upgrade

    Upgrade ubuntu/linux-riscv-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-42.42.1~24.04.1
  44. Upgrade

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

    Fixed in 7.0.0-42.42
  45. Upgrade

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

    Fixed in 7.0.0-1016.17
  46. Upgrade

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

    Fixed in 7.0.0-1016.18
  47. Upgrade

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

    Fixed in 7.0.0-1017.17
  48. Upgrade

    Upgrade ubuntu/linux-oem-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1017.17
  49. Upgrade

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

    Fixed in 7.0.0-1015.16
  50. Upgrade

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

    Fixed in 7.0.0-42.42.1
  51. Compensating control

    In nfc_llcp_recv_hdlc(), guard access to skb->data[2] with pskb_may_pull() so the sequence byte is present and linear; drop truncated I, RR, and RNR PDUs without sending a DM reply.

Event History

Oct 18, 2026
CVE Published
via MITRE·03:15 PM
Data Sourced
via MITRE·03:15 PM
Description
Data Sourced
via OSV·03:15 PM
DescriptionAffected Software
Data Sourced
via NVD·04:16 PM
Description
Oct 20, 2026
Data Sourced
via Microsoft·08:08 AM
DescriptionSeverityWeaknessAffected Software
Nov 10, 2026
Data Sourced
via OSV·02:52 AM
Severity

Frequently Asked Questions

1

What must an attacker be able to do to reach the vulnerable path?

An attacker needs to send a malformed, truncated LLCP I, RR, or RNR PDU to the affected NFC LLCP receive path. The malformed frame contains only the two-byte LLCP header, causing the kernel to read a missing sequence byte from uninitialised skb tailroom.

2

Are valid LLCP frames affected by the fix?

No. RR and RNR PDUs normally include both the LLCP header and sequence byte, and I PDUs are longer; the added length check rejects only truncated malformed PDUs.

3

What behavior indicates the system has the remediation?

The receive handler checks that the sequence byte is present and linear with pskb_may_pull() before calling nfc_llcp_ns() or nfc_llcp_nr(). Truncated I, RR, and RNR PDUs are dropped without sending a DM reply.

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