EDAC/altera: Drop __init from ECC setup paths for re-probe safety

Overview

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

EDAC/altera: Drop __init from ECC setup paths for re-probe safety

Sashiko reports:

"Does suppressing sysfs unbinding fully prevent the execution of freed __init memory? If altr_sysmgr_regmap_lookup_by_phandle() returns -EPROBE_DEFER, the probe is deferred until after __init memory is freed."

The a10 EDAC .setup callbacks (sdmmc, ethernet, nand, dma, usb, qspi) and their helpers (altr_init_a10_ecc_device_type, altr_init_a10_ecc_block) were marked __init. These run from the probe path, which may execute after init memory is freed -- e.g. a probe deferred via -EPROBE_DEFER that only succeeds once a late/module dependency appears, or a manual unbind/rebind. Calling __init code then dereferences freed memory. Remove __init so these functions remain valid at runtime.

Affected

• Linux >= 788586efd116d6d7d05985881eda503333e702b4 < 9846b85c2eb8b749c3f14bdcc31b1070f6aabba8
• Linux >= 788586efd116d6d7d05985881eda503333e702b4 < 4ec26cb7984740941892ad21fa974963c198bfaa
• Linux >= 788586efd116d6d7d05985881eda503333e702b4 < b62a264163ca51bee04785c581344751812395df
• Linux 5.2

Remediation

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