[PATCH RESEND v2 0/2] nfc: st21nfca: fix SE APDU request race condition

[Joas Antonio dos Santos via B4 Relay]

Fix a race between the timeout work handler and the EVT_TRANSMIT_DATA
event handler that can lead to a double invocation of the SE APDU
callback, resulting in use-after-free or double-free of the callback
context.

Split into two patches:
  1/2: Add a spinlock to serialize access to bwi_active, cb, and
       cb_context across the three concurrent paths.
  2/2: Use the lock to guard against double completion and reject
       overlapping requests.

Changes since v1:
  - Use spinlock instead of plain bwi_active flag checks (Simon Horman)
  - Split into 2-patch series: locking infrastructure + completion fix
  - Move bwi_active = true before mod_timer()
  - Copy cb/cb_context under lock, invoke after releasing
  - Reject overlapping se_io requests with -EBUSY
  - Drop Assisted-by trailer

---
Joas Antonio dos Santos (2):
      nfc: st21nfca: add spinlock to serialize SE APDU request state
      nfc: st21nfca: prevent double completion of SE APDU request

 drivers/nfc/st21nfca/se.c       | 36 ++++++++++++++++++++++++++++++++----
 drivers/nfc/st21nfca/st21nfca.h |  2 ++
 2 files changed, 34 insertions(+), 4 deletions(-)
---
base-commit: 602042bf29f6efde39cfb5fdd9289bf4854bc0c5
change-id: 20261108-st21nfca-v2-f4c5f861e416

Best regards,
-- 
Joas Antonio dos Santos <joasantonio108@xxxxxxxxx>