CVE-2026-98931

In the Linux kernel, the following vulnerability has been resolved:

mtd: spinand: fix NULL pointer dereference with no ECC engine

When "nand-no-ecc-engine" is set in DT, nanddev_get_ecc_engine() takes
the NAND_ECC_ENGINE_TYPE_NONE path and returns success while leaving
nand->ecc.engine NULL. The SPI-NAND code nevertheless dereferences it
unconditionally to test for a pipelined engine, so probing such a
device oopses immediately.

Rather than open-coding the test three times, add a
nand_ecc_is_pipelined() helper to the NAND core that folds the NULL
check into the integration comparison, and use it everywhere. Future
callers then cannot reintroduce the problem.