net: convert sock.sk_refcnt 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.
This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.
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 S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 90fd38d..643302b 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4495,7 +4495,7 @@ static int packet_seq_show(struct seq_file *seq, void *v)
seq_printf(seq,
"%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
s,
- atomic_read(&s->sk_refcnt),
+ refcount_read(&s->sk_refcnt),
s->sk_type,
ntohs(po->num),
po->ifindex,