[SEVERE] Re: [REGRESSION] Linux kernel 6.12.75 fails to compile with -Werror=implicit-function-declaration

[Aditya Garg <gargaditya08@live.com>]

The faulty commit seems to be f8f73bf0f8a57ee9b86792456bd42079bc98c6b7 on 6.12

> On 4 Mar 2026, at 11:22 PM, Aditya Garg <gargaditya08@live.com> wrote:
> 
> Looks like kernel 6.12, 6.6 and 6.1 series got only one part of the three patches sent, thus causing this regression.
> 
> Marking this as SEVERE, please forgive me if I did wrong.
> 
>> On 4 Mar 2026, at 11:05 PM, Aditya Garg <gargaditya08@live.com> wrote:
>> 
>> Hi
>> 
>> I found out that Linux kernel 6.12.75 failed to compiled in my automatic builds. The compiler throws the error:
>> 
>> arch/x86/kernel/setup.c: In function 'ima_get_kexec_buffer':
>> arch/x86/kernel/setup.c:380:15: error: implicit declaration of function 'ima_validate_range' [-Werror=implicit-function-declaration]
>> 380 |         ret = ima_validate_range(ima_kexec_buffer_phys, ima_kexec_buffer_size);
>>   |               ^~~~~~~~~~~~~~~~~~
>> cc1: some warnings being treated as errors
>> make[7]: *** [scripts/Makefile.build:229: arch/x86/kernel/setup.o] Error 1
>> make[6]: *** [scripts/Makefile.build:466: arch/x86/kernel] Error 2
>> make[5]: *** [scripts/Makefile.build:466: arch/x86] Error 2
>> 
>> Upon searching a bit, I found out that failure of this patch to be backported seems to be main reason:
>> 
>> https://lore.kernel.org/all/20251231061609.907170-2-harshit.m.mogalapalli@oracle.com/
>> 
>> Looks like this series itself was not properly backported.
>> 
>> I am not sure if any other kernel version is affected. I currently build 6.19 and 6.12 series for my use.
>> 
>> Thanks!
>> Aditya