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 spectrebhbloop_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 ismidrinrangelist() will walk off the end when it doesn't find a match. With UBSAN enabled, this leads to a crash during boot when ismidrinrangelist() is inlined (which was more common prior to c8c2647e69be ("arm64: Make midrinrangelist() an exported function")):
| Internal error: aarch64 BRK: 00000000f2000001 [#1] PREEMPT SMP | pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : spectrebhbloopaffected+0x28/0x30 | lr : isspectrebhbaffected+0x170/0x190 | [...] | Call trace: | spectrebhbloopaffected+0x28/0x30 | updatecpucapabilities+0xc0/0x184 | initcpufeatures+0x188/0x1a4 | cpuinfostorebootcpu+0x4c/0x60 | smppreparebootcpu+0x38/0x54 | startkernel+0x8c/0x478 | _primaryswitched+0xc8/0xd4 | Code: 6b09011f 54000061 52801080 d65f03c0 (d4200020) | ---[ end trace 0000000000000000 ]--- | Kernel panic - not syncing: aarch64 BRK: Fatal exception
Add the missing sentinel entries.