From 6f2ce5a13545ecb4e2a16460fb0dce4d6b527efa Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin Date: Wed, 12 Mar 2025 22:51:00 +0900 Subject: [PATCH] Bluetooth: L2CAP: handle NULL sock pointer in l2cap_sock_alloc BugLink: https://bugs.launchpad.net/bugs/2102118 commit 5f397409f8ee5bc82901eeaf799e1cbc4f8edcf1 upstream. A NULL sock pointer is passed into l2cap_sock_alloc() when it is called from l2cap_sock_new_connection_cb() and the error handling paths should also be aware of it. Seemingly a more elegant solution would be to swap bt_sock_alloc() and l2cap_chan_create() calls since they are not interdependent to that moment but then l2cap_chan_create() adds the soon to be deallocated and still dummy-initialized channel to the global list accessible by many L2CAP paths. The channel would be removed from the list in short period of time but be a bit more straight-forward here and just check for NULL instead of changing the order of function calls. Found by Linux Verification Center (linuxtesting.org) with SVACE static analysis tool. Fixes: 7c4f78cdb8e7 ("Bluetooth: L2CAP: do not leave dangling sk pointer on error in l2cap_sock_create()") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin Reviewed-by: Kuniyuki Iwashima Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 245d48c1ba3e7a1779c2f4cbc6f581ddc8a78e22 linux-6.6.y) [koichiroden: follow-up fix from v6.6.78] Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- net/bluetooth/l2cap_sock.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 31fbb562641f..223756d26660 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1886,7 +1886,8 @@ static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, chan = l2cap_chan_create(); if (!chan) { sk_free(sk); - sock->sk = NULL; + if (sock) + sock->sk = NULL; return NULL; }