Sourabh Jain <[email protected]> writes: > 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 <[email protected]> > Closes: > https://lore.kernel.org/all/[email protected]/
Nice catch. Indeed seems to be missed in the Fixes patch. I think you might want to Cc: stable too, so that it is auto backported to previous stable kernel releases too. The Fixes patch was added in v5.19 kernel, maybe we weren't testing KASAN + Kdump, but it's worth backporting to all stable kernel releases, IMO. LGTM, please feel free to add: Reviewed-by: Ritesh Harjani (IBM) <[email protected]>
