btrfs: convert extent_map.refs from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Elena Reshetova
2017-03-03 10:55:12 +02:00
committed by David Sterba
parent 9b64f57ddf
commit 490b54d6fb
6 changed files with 12 additions and 11 deletions

View File

@@ -213,7 +213,7 @@ TRACE_EVENT_CONDITION(btrfs_get_extent,
__entry->block_start = map->block_start;
__entry->block_len = map->block_len;
__entry->flags = map->flags;
__entry->refs = atomic_read(&map->refs);
__entry->refs = refcount_read(&map->refs);
__entry->compress_type = map->compress_type;
),