From babddbfb7d7d70ae7f10fedd75a45d8ad75fdddf Mon Sep 17 00:00:00 2001 From: Haibo Li Date: Mon, 9 Oct 2023 15:37:48 +0800 Subject: [PATCH] kasan: print the original fault addr when access invalid shadow when the checked address is illegal,the corresponding shadow address from kasan_mem_to_shadow may have no mapping in mmu table. Access such shadow address causes kernel oops. Here is a sample about oops on arm64(VA 39bit) with KASAN_SW_TAGS and KASAN_OUTLINE on: [ffffffb80aaaaaaa] pgd=000000005d3ce003, p4d=000000005d3ce003, pud=000000005d3ce003, pmd=0000000000000000 Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 3 PID: 100 Comm: sh Not tainted 6.6.0-rc1-dirty #43 Hardware name: linux,dummy-virt (DT) pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __hwasan_load8_noabort+0x5c/0x90 lr : do_ib_ob+0xf4/0x110 ffffffb80aaaaaaa is the shadow address for efffff80aaaaaaaa. The problem is reading invalid shadow in kasan_check_range. The generic kasan also has similar oops. It only reports the shadow address which causes oops but not the original address. Commit 2f004eea0fc8("x86/kasan: Print original address on #GP") introduce to kasan_non_canonical_hook but limit it to KASAN_INLINE. This patch extends it to KASAN_OUTLINE mode. Link: https://lkml.kernel.org/r/20231009073748.159228-1-haibo.li@mediatek.com Fixes: 2f004eea0fc8("x86/kasan: Print original address on #GP") Signed-off-by: Haibo Li Reviewed-by: Andrey Konovalov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: AngeloGioacchino Del Regno Cc: Dmitry Vyukov Cc: Haibo Li Cc: Matthias Brugger Cc: Vincenzo Frascino Cc: Arnd Bergmann Cc: Kees Cook Signed-off-by: Andrew Morton --- include/linux/kasan.h | 6 +++--- mm/kasan/report.c | 4 +--- 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 842623d708c2..6dbb5ded3cf9 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -466,10 +466,10 @@ static inline void kasan_free_module_shadow(const struct vm_struct *vm) {} #endif /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */ -#ifdef CONFIG_KASAN_INLINE +#ifdef CONFIG_KASAN void kasan_non_canonical_hook(unsigned long addr); -#else /* CONFIG_KASAN_INLINE */ +#else /* CONFIG_KASAN */ static inline void kasan_non_canonical_hook(unsigned long addr) { } -#endif /* CONFIG_KASAN_INLINE */ +#endif /* CONFIG_KASAN */ #endif /* LINUX_KASAN_H */ diff --git a/mm/kasan/report.c b/mm/kasan/report.c index ca4b6ff080a6..3974e4549c3e 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -621,9 +621,8 @@ void kasan_report_async(void) } #endif /* CONFIG_KASAN_HW_TAGS */ -#ifdef CONFIG_KASAN_INLINE /* - * With CONFIG_KASAN_INLINE, accesses to bogus pointers (outside the high + * With CONFIG_KASAN, accesses to bogus pointers (outside the high * canonical half of the address space) cause out-of-bounds shadow memory reads * before the actual access. For addresses in the low canonical half of the * address space, as well as most non-canonical addresses, that out-of-bounds @@ -659,4 +658,3 @@ void kasan_non_canonical_hook(unsigned long addr) pr_alert("KASAN: %s in range [0x%016lx-0x%016lx]\n", bug_type, orig_addr, orig_addr + KASAN_GRANULE_SIZE - 1); } -#endif