CVE-2025-68308can: kvaser_usb: leaf: Fix potential infinite loop in command parsers

Official description

In the Linux kernel, the following vulnerability has been resolved: can: kvaser_usb: leaf: Fix potential infinite loop in command parsers The `kvaser_usb_leaf_wait_cmd()` and `kvaser_usb_leaf_read_bulk_callback` functions contain logic to zero-length commands. These commands are used to align data to the USB endpoint's wMaxPacketSize boundary. The driver attempts to skip these placeholders by aligning the buffer position `pos` to the next packet boundary using `round_up()` function. However, if zero-length command is found exactly on a packet boundary (i.e., `pos` is a multiple of wMaxPacketSize, including 0), `round_up` function will return the unchanged value of `pos`. This prevents `pos` to be increased, causing an infinite loop in the parsing logic. This patch fixes this in the function by using `pos + 1` instead. This ensures that even if `pos` is on a boundary, the calculation is based on `pos + 1`, forcing `round_up()` to always return the next aligned boundary.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/58343e0a4d43699f0e2f5b169384bbe4c0217add
• https://git.kernel.org/stable/c/69c7825df64e24dc15d31631a1fc9145324b1345
• https://git.kernel.org/stable/c/028e89c7e8b4346302e88df01cc50e0a1f05791a
• https://git.kernel.org/stable/c/e9dd83a75a7274edef21682c823bf0b66d7b6b7f
• https://git.kernel.org/stable/c/0897cea266e39166a36111059ba147192b36592f
• https://git.kernel.org/stable/c/bd8135a560cf6e64f0b98ed4daadf126a38f7f48
• https://git.kernel.org/stable/c/0c73772cd2b8cc108d5f5334de89ad648d89b9ec