[PATCH v2 0/2] can: kvaser_usb: validate values received from the device

[Joas Antonio dos Santos via B4 Relay <devnull+joasantonio108.gmail.com@kernel.org>]

Two fixes for values that kvaser_usb takes from the USB device without
checking them.

Patch 1 rejects hydra commands whose length is shorter than a standard
command.  A length of zero otherwise stalls the command loops, and a
short extended command makes the handlers read past the command.

Patch 2 rejects devices that report zero max outstanding tx, which
otherwise leads to a division by zero.

These issues were found with the help of an LLM-based code review tool
(Claude).  I checked the code paths by hand against v7.4-rc3 and
reviewed the fixes myself.  They are build-tested only (W=1, arm64); I
do not have the hardware to test them at runtime.

---
Changes in v2:
- Patch 1: require at least sizeof(struct kvaser_cmd) instead of the
  4-byte header, so that the extended command handlers do not read past
  a short command (sashiko review of v1).  Subject changed, it was
  "can: kvaser_usb: hydra: reject commands shorter than the header".
- Patch 2: unchanged.
- Link to v1: https://lore.kernel.org/r/20261110-kvaser-usb-validate-v1-0-f266b85aa908@gmail.com

---
Joas Antonio dos Santos (2):
      can: kvaser_usb: hydra: reject commands shorter than a standard command
      can: kvaser_usb: reject devices reporting zero max outstanding tx

 drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c  | 6 ++++++
 drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 8 +++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)
---
base-commit: b3dfbde62cf1981c4638939c159dfd087b7a72e9
change-id: 20261110-kvaser-usb-validate-33c2e34b63bf

Best regards,
-- 
Joas Antonio dos Santos <joasantonio108@gmail.com>