Messages in this thread |  | | Date | Sat, 31 Dec 2022 21:13:05 -0800 | Subject | Re: [PATCH qemu] x86: don't let decompressed kernel image clobber setup_data | From | "H. Peter Anvin" <> |
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On 12/31/22 20:55, Mika Penttilä wrote: >> >> If decompression does clobber the data, then we *also* need to figure >> out why that is. There are basically three possibilities: >> >> 1. If physical KASLR is NOT used: >> >> a. The boot loader doesn't honor the kernel safe area properly; >> b. Somewhere in the process a bug in the calculation of the >> kernel safe area has crept in. >> >> 2. If physical KASLR IS used: >> >> The decompressor doesn't correctly keep track of nor relocate >> all the keep-out zones before picking a target address. > > Seems setup_data is not included in those mem_avoid regions. >
[facepalm]
>> >> One is a bootloader bug, two is a kernel bugs. My guess is (2) is the >> culprit, but (1b) should be checked, too. >>
Correction: two are kernel bugs, i.e. (1b) and (2) are both kernel bugs.
-hpa
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