EDAC/i10nm: Skip DIMM enumeration on a disabled memory controller

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: EDAC/i10nm: Skip DIMM enumeration on a disabled memory controller When loading the i10nm_edac driver on some Intel Granite Rapids servers, a call trace may appear as follows: UBSAN: shift-out-of-bounds in drivers/edac/skx_common.c:453:16 shift exponent -66 is negative ... __ubsan_handle_shift_out_of_bounds+0x1e3/0x390 skx_get_dimm_info.cold+0x47/0xd40 [skx_edac_common] i10nm_get_dimm_config+0x23e/0x390 [i10nm_edac] skx_register_mci+0x159/0x220 [skx_edac_common] i10nm_init+0xcb0/0x1ff0 [i10nm_edac] ... This occurs because some BIOS may disable a memory controller if there aren't any memory DIMMs populated on this memory controller. The DIMMMTR register of this disabled memory controller contains the invalid value ~0, resulting in the call trace above. Fix this call trace by skipping DIMM enumeration on a disabled memory controller.

References

• https://git.kernel.org/stable/c/8100b6c0f9089d5b156642b81270ce27fff17490
• https://git.kernel.org/stable/c/1652f14cf3bef5a4baa232de954fc22bdcaa78fe
• https://git.kernel.org/stable/c/c20da24272f1ac79e9f9083bba577d049cd02bbb
• https://git.kernel.org/stable/c/2e6fe1bbefd9c059c3787d1c620fe67343a94dff