From f2377d4eaab2aabe1938b3974b5b94f5ba4c7ead Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Thu, 5 Nov 2015 18:50:48 -0800 Subject: mm/kasan: don't use kasan shadow pointer in generic functions We can't use generic functions like print_hex_dump to access kasan shadow region. This require us to setup another kasan shadow region for the address passed (kasan shadow address). Some architectures won't be able to do that. Hence make a copy of the shadow region row and pass that to generic functions. Signed-off-by: Aneesh Kumar K.V Reviewed-by: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/kasan/report.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'mm/kasan/report.c') diff --git a/mm/kasan/report.c b/mm/kasan/report.c index d269f2087faf..c5367089703c 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -164,14 +164,20 @@ static void print_shadow_for_address(const void *addr) for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) { const void *kaddr = kasan_shadow_to_mem(shadow_row); char buffer[4 + (BITS_PER_LONG/8)*2]; + char shadow_buf[SHADOW_BYTES_PER_ROW]; snprintf(buffer, sizeof(buffer), (i == 0) ? ">%p: " : " %p: ", kaddr); - + /* + * We should not pass a shadow pointer to generic + * function, because generic functions may try to + * access kasan mapping for the passed address. + */ kasan_disable_current(); + memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW); print_hex_dump(KERN_ERR, buffer, DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1, - shadow_row, SHADOW_BYTES_PER_ROW, 0); + shadow_buf, SHADOW_BYTES_PER_ROW, 0); kasan_enable_current(); if (row_is_guilty(shadow_row, shadow)) -- cgit v1.2.3-59-g8ed1b