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

[Aditya Garg]

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@xxxxxxxxxx/

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