published September 4, 2026
In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: add data_len bound checks to activation parameter extractors
nci_extract_activation_params_iso_dep() and
nci_extract_activation_params_nfc_dep() read an inner length byte from
the NCI RF_INTF_ACTIVATED_NTF payload and use it to memcpy() into fixed
kernel buffers, but neither function receives the caller-validated
activation_params_len. A crafted NCI notification with
activation_params_len=1 and an inner length byte of up to 20 (NFC-A) or
50 (NFC-B) causes memcpy() to read that many bytes past the one valid
byte in the activation params region -- a slab out-of-bounds read of
kernel memory adjacent to the NCI skb.
The sibling nci_extract_rf_params_*() family was given equivalent
protection by commit 571dcbeb8e63 ("net: nfc: nci: Fix parameter
validation for packet data"), but the two activation parameter
extractors were not updated at that time.
Add a data_len parameter to both functions, guard against an empty
region before consuming the inner length byte, decrement the remaining
count after consuming it, and clamp the copy length to what is actually
available. Update both call sites to pass ntf.activation_params_len,
which is already validated against the skb at ntf.c:801.