From aef6b8afe2fe53b2de604591ba211fcaae0a8d42 Mon Sep 17 00:00:00 2001 From: Samuel Page Date: Fri, 26 Jun 2026 10:03:01 +0100 Subject: 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. Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support") Fixes: e8c0dacd9836 ("NFC: Update names and structs to NCI spec 1.0 d18") Link: https://lore.kernel.org/netdev/20260623172109.1105965-2-horms@kernel.org/ Cc: stable@vger.kernel.org Assisted-by: Bynario AI Signed-off-by: Samuel Page Link: https://patch.msgid.link/20260626090301.2139500-1-sam@bynar.io Signed-off-by: David Heidelberg --- net/nfc/nci/ntf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c index 87f76a29f0ec..f5c9a8ab7ec1 100644 --- a/net/nfc/nci/ntf.c +++ b/net/nfc/nci/ntf.c @@ -440,7 +440,7 @@ void nci_clear_target_list(struct nci_dev *ndev) static int nci_rf_discover_ntf_packet(struct nci_dev *ndev, const struct sk_buff *skb) { - struct nci_rf_discover_ntf ntf; + struct nci_rf_discover_ntf ntf = {}; const __u8 *data; bool add_target = true; @@ -710,7 +710,7 @@ static int nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev, const struct sk_buff *skb) { struct nci_conn_info *conn_info; - struct nci_rf_intf_activated_ntf ntf; + struct nci_rf_intf_activated_ntf ntf = {}; const __u8 *data; int err = NCI_STATUS_OK; -- cgit v1.2.3