From: Ignat Korchagin ignat@cloudflare.com
[ Upstream commit 3945c799f12b8d1f49a3b48369ca494d981ac465 ]
bt_sock_alloc() attaches allocated sk object to the provided sock object. If rfcomm_dlc_alloc() fails, we release the sk object, but leave the dangling pointer in the sock object, which may cause use-after-free.
Fix this by swapping calls to bt_sock_alloc() and rfcomm_dlc_alloc().
Signed-off-by: Ignat Korchagin ignat@cloudflare.com Reviewed-by: Kuniyuki Iwashima kuniyu@amazon.com Reviewed-by: Eric Dumazet edumazet@google.com Link: https://patch.msgid.link/20241014153808.51894-4-ignat@cloudflare.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/bluetooth/rfcomm/sock.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c index cbff37b327340..c32a2374638b7 100644 --- a/net/bluetooth/rfcomm/sock.c +++ b/net/bluetooth/rfcomm/sock.c @@ -274,13 +274,13 @@ static struct sock *rfcomm_sock_alloc(struct net *net, struct socket *sock, struct rfcomm_dlc *d; struct sock *sk;
- sk = bt_sock_alloc(net, sock, &rfcomm_proto, proto, prio, kern); - if (!sk) + d = rfcomm_dlc_alloc(prio); + if (!d) return NULL;
- d = rfcomm_dlc_alloc(prio); - if (!d) { - sk_free(sk); + sk = bt_sock_alloc(net, sock, &rfcomm_proto, proto, prio, kern); + if (!sk) { + rfcomm_dlc_free(d); return NULL; }