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 08895d8..4d15112 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -142,7 +142,7 @@ struct scrub_parity {
int stripe_len;
- atomic_t refs;
+ refcount_t refs;
struct list_head spages;
@@ -2822,12 +2822,12 @@ static inline int scrub_calc_parity_bitmap_len(int nsectors)
static void scrub_parity_get(struct scrub_parity *sparity)
{
- atomic_inc(&sparity->refs);
+ refcount_inc(&sparity->refs);
}
static void scrub_parity_put(struct scrub_parity *sparity)
{
- if (!atomic_dec_and_test(&sparity->refs))
+ if (!refcount_dec_and_test(&sparity->refs))
return;
scrub_parity_check_and_repair(sparity);
@@ -2879,7 +2879,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
sparity->scrub_dev = sdev;
sparity->logic_start = logic_start;
sparity->logic_end = logic_end;
- atomic_set(&sparity->refs, 1);
+ refcount_set(&sparity->refs, 1);
INIT_LIST_HEAD(&sparity->spages);
sparity->dbitmap = sparity->bitmap;
sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
--
2.7.4
--
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