mm: prevent KASAN false positives in kmemleak

When kmemleak dumps contents of leaked objects it reads whole objects
regardless of user-requested size.  This upsets KASAN.  Disable KASAN
checks around object dump.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Dmitry Vyukov <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index e6429926e95741055fe1aa87a3082e6ed073f909..04320d3adbef9922edda52e43cc516463e9e33c6 100644 (file)
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -307,8 +307,10 @@ static void hex_dump_object(struct seq_file *seq,
        len = min_t(size_t, object->size, HEX_MAX_LINES * HEX_ROW_SIZE);
 
        seq_printf(seq, "  hex dump (first %zu bytes):\n", len);
+       kasan_disable_current();
        seq_hex_dump(seq, "    ", DUMP_PREFIX_NONE, HEX_ROW_SIZE,
                     HEX_GROUP_SIZE, ptr, len, HEX_ASCII);
+       kasan_enable_current();
 }
 
 /*