KASAN instrumentation is intended to be disabled for the kexec core code, but the existing Makefile entry misses the object suffix. As a result, the flag is not applied correctly to core_$(BITS).o. So when KASAN is enabled, kexec_copy_flush and copy_segments in kexec/core_64.c are instrumented, which can result in accesses to shadow memory via normal address translation paths. Since these run with the MMU disabled, such accesses may trigger page faults (bad_page_fault) that cannot be handled in the kdump path, ultimately causing a hang and preventing the kdump kernel from booting. The same is true for kexec as well, since the same functions are used there. Update the entry to include the “.o” suffix so that KASAN instrumentation is properly disabled for this object file. Fixes: 2ab2d5794f14 ("powerpc/kasan: Disable address sanitization in kexec paths") Reported-by: Venkat Rao Bagalkote Closes: https://lore.kernel.org/all/1dee8891-8bcc-46b4-93f3-fc3a774abd5b@linux.ibm.com/ Cc: Aditya Gupta Cc: Daniel Axtens Cc: Hari Bathini Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Shivang Upadhyay Cc: stable@vger.kernel.org Reviewed-by: Ritesh Harjani (IBM) Tested-by: Venkat Rao Bagalkote Acked-by: Mahesh Salgaonkar Reviewed-by: Aboorva Devarajan Tested-by: Aboorva Devarajan Signed-off-by: Sourabh Jain --- Changelog: v3: - Cc stable mailing list - No functional changes v2: - Add Reviewed-by, Acked-by and Tested-by tags - No functional changes - https://lore.kernel.org/all/20260403190123.1383198-1-sourabhjain@linux.ibm.com/ v1: - https://lore.kernel.org/all/20260321053121.614022-1-sourabhjain@linux.ibm.com/ --- arch/powerpc/kexec/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile index 470eb0453e17..ec7a0eed75dc 100644 --- a/arch/powerpc/kexec/Makefile +++ b/arch/powerpc/kexec/Makefile @@ -16,4 +16,4 @@ GCOV_PROFILE_core_$(BITS).o := n KCOV_INSTRUMENT_core_$(BITS).o := n UBSAN_SANITIZE_core_$(BITS).o := n KASAN_SANITIZE_core.o := n -KASAN_SANITIZE_core_$(BITS) := n +KASAN_SANITIZE_core_$(BITS).o := n -- 2.52.0