The patch titled
Subject: mm/kasan: don't use kasan shadow pointer in generic functions
has been added to the -mm tree. Its filename is
mm-kasan-dont-use-kasan-shadow-pointer-in-generic-functions.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-kasan-dont-use-kasan-shadow-pointer-in-generic-functions.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-kasan-dont-use-kasan-shadow-pointer-in-generic-functions.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
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
mm-kasan-rename-kasan_enabled-to-kasan_report_enabled.patch
mm-kasan-module_vaddr-is-not-available-on-all-archs.patch
mm-kasan-dont-use-kasan-shadow-pointer-in-generic-functions.patch
mm-kasan-prevent-deadlock-in-kasan-reporting.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
