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@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
fs/btrfs/scrub.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index b0251eb..c9406bf 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -64,7 +64,7 @@ struct scrub_ctx;
#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
struct scrub_recover {
- atomic_t refs;
+ refcount_t refs;
struct btrfs_bio *bbio;
u64 map_length;
};
@@ -857,12 +857,12 @@ static void scrub_fixup_nodatasum(struct btrfs_work *work)
static inline void scrub_get_recover(struct scrub_recover *recover)
{
- atomic_inc(&recover->refs);
+ refcount_inc(&recover->refs);
}
static inline void scrub_put_recover(struct scrub_recover *recover)
{
- if (atomic_dec_and_test(&recover->refs)) {
+ if (refcount_dec_and_test(&recover->refs)) {
btrfs_put_bbio(recover->bbio);
kfree(recover);
}
@@ -1343,7 +1343,7 @@ static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
return -ENOMEM;
}
- atomic_set(&recover->refs, 1);
+ refcount_set(&recover->refs, 1);
recover->bbio = bbio;
recover->map_length = mapped_length;
--
2.7.4
