The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 2e07e8348ea454615e268222ae3fc240421be768 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023122844-parmesan-autism-1891@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
2e07e8348ea4 ("Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg") f4b41f062c42 ("net: remove noblock parameter from skb_recv_datagram()") 42bf50a1795a ("can: isotp: support MSG_TRUNC flag when reading from socket") 30ffd5332e06 ("can: isotp: return -EADDRNOTAVAIL when reading from unbound socket") c5755214623d ("mctp: tests: Add key state tests") 62a2b005c6d6 ("mctp: tests: Rename FL_T macro to FL_TO") 1e5e9250d422 ("mctp: Add input reassembly tests") 8892c0490779 ("mctp: Add route input to socket tests") b504db408c34 ("mctp: Add packet rx tests") 161eba50e183 ("mctp: Add initial test structure and fragmentation test") 833ef3b91de6 ("mctp: Populate socket implementation") 4d8b9319282a ("mctp: Add neighbour implementation") 889b7da23abf ("mctp: Add initial routing framework") 583be982d934 ("mctp: Add device handling and netlink interface") 60fc63981693 ("mctp: Add sockaddr_mctp to uapi") 2c8e2e9aec79 ("mctp: Add base packet definitions") 8f601a1e4f8c ("mctp: Add base socket/protocol definitions") bc49d8169aa7 ("mctp: Add MCTP base") 29df44fa52b7 ("af_unix: Implement ->read_sock() for sockmap") fe0bdbde0756 ("net: add pf_family_names[] for protocol family")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 2e07e8348ea454615e268222ae3fc240421be768 Mon Sep 17 00:00:00 2001 From: Hyunwoo Kim v4bel@theori.io Date: Sat, 9 Dec 2023 05:55:18 -0500 Subject: [PATCH] Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg
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
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c index 336a76165454..b93464ac3517 100644 --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -309,11 +309,14 @@ 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, &err); if (!skb) { if (sk->sk_shutdown & RCV_SHUTDOWN) - return 0; + err = 0;
+ release_sock(sk); return err; }
@@ -343,6 +346,8 @@ 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;