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

Overview

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.

Affected

• Linux >= f9d7c7265bcff7d9a17425a8cddf702e8fe159c2 < 77c449c9c946fc420008dc55cd30f53749c915e4
• Linux >= f9d7c7265bcff7d9a17425a8cddf702e8fe159c2 < 3c765fd5212c1bbc71568b1518a7ec963a7040b4
• Linux >= f9d7c7265bcff7d9a17425a8cddf702e8fe159c2 < 80e8b0ea73ba295e92dfb6cf1c41df9da64234c6
• Linux >= f9d7c7265bcff7d9a17425a8cddf702e8fe159c2 < fc2f651f520394893b14b75281a01e502bfa73bb
• Linux >= f9d7c7265bcff7d9a17425a8cddf702e8fe159c2 < b890e6163761ddb580cc74f43e15f8bbde15647e
• Linux 5.18

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.