From 2d73422ab840d2d31e711880046255f06326876c Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin Date: Thu, 6 Mar 2025 21:54:07 +0800 Subject: [PATCH] Bluetooth: L2CAP: handle NULL sock pointer in l2cap_sock_alloc maillist inclusion category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEANO CVE: CVE-2024-56605 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git/commit/?id=a723753d039fd9a6c5998340ac65f4d9e2966ba8 ---------------------------------------- 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: Dong Chenchen --- 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 c736aba98161..6537d0867fb3 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1864,7 +1864,8 @@ 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; } -- Gitee