nfc: nci: fix use of uninitialized memory in CORE_INIT_RSP parsing

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nci_core_init_rsp_packet_v1() and nci_core_init_rsp_packet_v2() parse
the CORE_INIT_RSP packet without validating that the skb contains
enough data. A malformed response (e.g. injected via virtual_ncidev)
can declare a large num_supported_rf_interfaces while providing
insufficient data, causing reads of uninitialized slab memory. This
is later used in nci_init_complete_req(), triggering a KMSAN
uninit-value warning.

Add skb length checks before accessing packet fields:
- Validate the skb has at least 1 byte for the status field.
- Validate the skb can hold the fixed-size header before parsing.
- In v2, bounds-check each variable-length rf_interface entry and its
  extension parameters within the parsing loop.
- In v1, verify the skb is large enough for both the variable-length
  rf_interfaces array and the trailing rsp_2 structure.

Reported-by: syzbot+46ca2592193f2fb3debc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=46ca2592193f2fb3debc
Fixes: bcd684aace ("net/nfc/nci: Support NCI 2.x initial sequence")
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Link: https://patch.msgid.link/20260527052625.3309581-1-yun.zhou@windriver.com
Signed-off-by: David Heidelberg <david@ixit.cz>

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Yun Zhou 2026-05-27 13:26:25 +08:00 • committed by David Heidelberg

parent 5718fc6219

commit d56575a259

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net/nfc/nci/rsp.c

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