In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: fix uninit-value in the RF discover/activated NTF handlers
nci_rf_discover_ntf_packet() and nci_rf_intf_activated_ntf_packet() each
parse a notification into an on-stack struct (nci_rf_discover_ntf /
nci_rf_intf_activated_ntf) that is not initialised. The RF
technology-specific parameters are only extracted when
rf_tech_specific_params_len is non-zero, so a notification that reports a
zero length leaves the rf_tech_specific_params union uninitialised - and
both handlers then pass it to nci_add_new_protocol(), which reads it:
- discover: nci_add_new_target() -> nci_add_new_protocol();
- activated: nci_target_auto_activated() -> nci_add_new_protocol().
nci_add_new_protocol() uses nfca_poll->nfcid1_len as both a branch
condition and a memcpy() length and copies nfcid1/sens_res/sel_res into
ndev->targets, which is later exposed to user space via NFC_CMD_GET_TARGET.
BUG: KMSAN: uninit-value in nci_add_new_protocol+0x624/0x6c0
nci_add_new_protocol+0x624/0x6c0
nci_ntf_packet+0x25b2/0x3c30
nci_rx_work+0x318/0x5d0
process_scheduled_works+0x84b/0x17a0
worker_thread+0xc10/0x11b0
kthread+0x376/0x500
Local variable ntf.i created at:
nci_ntf_packet+0xbc2/0x3c30
Zero-initialise both on-stack notifications so the union reads back as
zero when no technology-specific parameters are present.