The patch below does not apply to the 5.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From af92bad615be75c6c0d1b1c5b48178360250a187 Mon Sep 17 00:00:00 2001

From: Christophe Leroy christophe.leroy@c-s.fr Date: Fri, 6 Mar 2020 15:09:40 +0000 Subject: [PATCH] powerpc/kasan: Fix kasan_remap_early_shadow_ro()

At the moment kasan_remap_early_shadow_ro() does nothing, because k_end is 0 and k_cur < 0 is always true.

Change the test to k_cur != k_end, as done in kasan_init_shadow_page_tables()

Signed-off-by: Christophe Leroy christophe.leroy@c-s.fr Fixes: cbd18991e24f ("powerpc/mm: Fix an Oops in kasan_mmu_init()") Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/4e7b56865e01569058914c991143f5961b5d4719.158350733...

diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c index f19526e7d3dc..1a29cf469903 100644 --- a/arch/powerpc/mm/kasan/kasan_init_32.c +++ b/arch/powerpc/mm/kasan/kasan_init_32.c @@ -101,7 +101,7 @@ static void __init kasan_remap_early_shadow_ro(void)

kasan_populate_pte(kasan_early_shadow_pte, prot);

- for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) { + for (k_cur = k_start & PAGE_MASK; k_cur != k_end; k_cur += PAGE_SIZE) { pmd_t *pmd = pmd_ptr_k(k_cur); pte_t *ptep = pte_offset_kernel(pmd, k_cur);