CVE-2025-37929

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

arm64: errata: Add missing sentinels to Spectre-BHB MIDR arrays

Commit a5951389e58d (arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists) added some additional CPUs to the Spectre-BHB workaround, including some new arrays for designs that require new k values for the workaround to be effective.

Unfortunately, the new arrays omitted the sentinel entry and so is_midr_in_range_list() will walk off the end when it doesnt find a match. With UBSAN enabled, this leads to a crash during boot when is_midr_in_range_list() is inlined (which was more common prior to c8c2647e69be (arm64: Make  _midr_in_range_list() an exported function)):

| Internal error: aarch64 BRK: 00000000f2000001 [#1] PREEMPT SMP | pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=–) | pc : spectre_bhb_loop_affected+0x28/0x30 | lr : is_spectre_bhb_affected+0x170/0x190 | […] | Call trace: | spectre_bhb_loop_affected+0x28/0x30 | update_cpu_capabilities+0xc0/0x184 | init_cpu_features+0x188/0x1a4 | cpuinfo_store_boot_cpu+0x4c/0x60 | smp_prepare_boot_cpu+0x38/0x54 | start_kernel+0x8c/0x478 | __primary_switched+0xc8/0xd4 | Code: 6b09011f 54000061 52801080 d65f03c0 (d4200020) | —[ end trace 0000000000000000 ]— | Kernel panic - not syncing: aarch64 BRK: Fatal exception

Add the missing sentinel entries.

Affected Software

References

• https://git.kernel.org/stable/c/090c8714efe1c3c470301cc2f794c1ee2a57746c
• https://git.kernel.org/stable/c/333579202f09e260e8116321df4c55f80a19b160
• https://git.kernel.org/stable/c/3821cae9bd5a99a42d3d0be1b58e41f072cd4c4c
• https://git.kernel.org/stable/c/446289b8b36b2ee98dabf6388acbddcc33ed41be
• https://git.kernel.org/stable/c/6266b3509b2c6ebf2f9daf2239ff8eb60c5f5bd3
• https://git.kernel.org/stable/c/fee4d171451c1ad9e8aaf65fc0ab7d143a33bd72