The patch titled
Subject: mm/kasan: don't use kasan shadow pointer in generic functions
has been removed from the -mm tree. Its filename was
mm-kasan-dont-use-kasan-shadow-pointer-in-generic-functions.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
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 <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/report.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff -puN mm/kasan/report.c~mm-kasan-dont-use-kasan-shadow-pointer-in-generic-functions mm/kasan/report.c
--- a/mm/kasan/report.c~mm-kasan-dont-use-kasan-shadow-pointer-in-generic-functions
+++ a/mm/kasan/report.c
@@ -164,14 +164,20 @@ static void print_shadow_for_address(con
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))
_
Patches currently in -mm which might be from aneesh.kumar@xxxxxxxxxxxxxxxxxx are
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