CVE-2026-80794: nfc: nci: fix uninit-value in the RF discover/activated NTF handlers
In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: fix uninit-value in the RF discover/activated NTF handlers
ncirfdiscoverntfpacket() and ncirfintfactivatedntfpacket() each parse a notification into an on-stack struct (ncirfdiscoverntf / ncirfintfactivatedntf) that is not initialised. The RF technology-specific parameters are only extracted when rftechspecificparamslen is non-zero, so a notification that reports a zero length leaves the rftechspecificparams union uninitialised - and both handlers then pass it to nciaddnewprotocol(), which reads it:
- discover: nciaddnewtarget() -> nciaddnewprotocol(); - activated: ncitargetautoactivated() -> nciaddnewprotocol().
nciaddnewprotocol() uses nfcapoll->nfcid1len as both a branch condition and a memcpy() length and copies nfcid1/sensres/selres into ndev->targets, which is later exposed to user space via NFCCMDGETTARGET.
BUG: KMSAN: uninit-value in nciaddnewprotocol+0x624/0x6c0 nciaddnewprotocol+0x624/0x6c0 ncintfpacket+0x25b2/0x3c30 ncirxwork+0x318/0x5d0 processscheduledworks+0x84b/0x17a0 workerthread+0xc10/0x11b0 kthread+0x376/0x500 Local variable ntf.i created at: ncintfpacket+0xbc2/0x3c30
Zero-initialise both on-stack notifications so the union reads back as zero when no technology-specific parameters are present.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1119.126~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1125.134~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1124.133~20.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1120.130~20.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-202.212~20.04.1 - Upgrade
Upgrade
ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1113.117~20.04.1 - Upgrade
Upgrade
ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1114.120~20.04.1 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-197.207~20.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegra-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1070.72~20.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1116.122~20.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1113.117~20.04.2 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-202.212 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1119.126 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1125.134 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1124.133 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1120.130 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 5.15.0-1115.121 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 5.15.0-1102.110 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.15.0-1113.117 - Upgrade
Upgrade
ubuntu/linux-intel-iotgto a version that resolves this vulnerability.Fixed in 5.15.0-1114.120 - Upgrade
Upgrade
ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1111.116 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-197.207 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1114.115 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 5.15.0-1070.72 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegra-igxto a version that resolves this vulnerability.Fixed in 5.15.0-1059.59 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1116.122 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1103.105 - Upgrade
Upgrade
ubuntu/linux-intel-iot-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1111.115 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1118.127 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1119.126+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1125.134+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-202.212+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1120.130+fips1 - Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1
Event History
Frequently Asked Questions
What runtime condition causes the uninitialized data to be used?
An RF discover or RF interface activated notification must report a zero-length RF technology-specific parameter field. In that case, the on-stack parameter union is not populated before nci_add_new_protocol() reads it.
Where can the uninitialized data be exposed?
nci_add_new_protocol() can use the uninitialized nfca_poll nfcid1_len value as a memcpy length when populating ndev->targets. The resulting target data can later be exposed to user space through NFC_CMD_GET_TARGET.
Which notification paths are involved?
Both the RF discover notification path, through nci_add_new_target(), and the RF interface activated notification path, through nci_target_auto_activated(), reach nci_add_new_protocol() with the potentially uninitialized parameters.
Is there an available diagnostic signal for this issue?
The provided report shows KMSAN detecting an uninitialized-value access in nci_add_new_protocol(). A KMSAN-enabled kernel may therefore identify the issue when the affected notification handling path is exercised.