From: Hyunwoo Kim v4bel@theori.io

mainline inclusion from mainline-v6.7-rc7 commit 2e07e8348ea454615e268222ae3fc240421be768 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I8RXOD CVE: CVE-2023-51779

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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This can cause a race with bt_sock_ioctl() because bt_sock_recvmsg() gets the skb from sk->sk_receive_queue and then frees it without holding lock_sock. A use-after-free for a skb occurs with the following flow. ``` bt_sock_recvmsg() -> skb_recv_datagram() -> skb_free_datagram() bt_sock_ioctl() -> skb_peek() ``` Add lock_sock to bt_sock_recvmsg() to fix this issue.

Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Hyunwoo Kim v4bel@theori.io Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Conflicts: net/bluetooth/af_bluetooth.c Signed-off-by: Ziyang Xuan william.xuanziyang@huawei.com --- net/bluetooth/af_bluetooth.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c index 2f87f57e7a4f..14a917e70f3e 100644 --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -263,11 +263,14 @@ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, if (flags & MSG_OOB) return -EOPNOTSUPP;

+ lock_sock(sk); + skb = skb_recv_datagram(sk, flags, noblock, &err); if (!skb) { if (sk->sk_shutdown & RCV_SHUTDOWN) - return 0; + err = 0;

+ release_sock(sk); return err; }

@@ -293,6 +296,8 @@ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,

skb_free_datagram(sk, skb);

+ release_sock(sk); + if (flags & MSG_TRUNC) copied = skblen;