From 5492de7bd68504be4e1d01bd6d121e4b23d2152f Mon Sep 17 00:00:00 2001 From: Ignat Korchagin Date: Thu, 6 Feb 2025 11:06:47 +0800 Subject: [PATCH 1/2] Bluetooth: L2CAP: do not leave dangling sk pointer on error in l2cap_sock_create() stable inclusion from stable-v5.10.231 commit daa13175a6dea312a76099066cb4cbd4fc959a84 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/stable/linux.git/commit/?id=daa13175a6dea312a76099066cb4cbd4fc959a84 -------------------------------- [ Upstream commit 7c4f78cdb8e7501e9f92d291a7d956591bf73be9 ] bt_sock_alloc() allocates the sk object and attaches it to the provided sock object. On error l2cap_sock_alloc() frees the sk object, but the dangling pointer is still attached to the sock object, which may create use-after-free in other code. Signed-off-by: Ignat Korchagin Reviewed-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20241014153808.51894-3-ignat@cloudflare.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Lin Ruifeng --- net/bluetooth/l2cap_sock.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index bcada51cb01e..9f4a4391f6fe 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1629,6 +1629,7 @@ static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, chan = l2cap_chan_create(); if (!chan) { sk_free(sk); + sock->sk = NULL; return NULL; } -- Gitee From a85c8623ea522fedd9509e01598f70b3777397cd Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin Date: Thu, 6 Feb 2025 11:06:48 +0800 Subject: [PATCH 2/2] Bluetooth: L2CAP: handle NULL sock pointer in l2cap_sock_alloc mainline inclusion from mainline-v6.14-rc1 commit 5f397409f8ee5bc82901eeaf799e1cbc4f8edcf1 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/torvalds/linux.git/commit/?id=5f397409f8ee5bc82901eeaf799e1cbc4f8edcf1 -------------------------------- 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: Lin Ruifeng --- 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 9f4a4391f6fe..05fea988b4cf 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1629,7 +1629,8 @@ 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