From: Luiz Augusto von Dentz luiz.von.dentz@intel.com
mainline inclusion from mainline-v6.10-rc7 commit f1a8f402f13f94263cf349216c257b2985100927 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGEK1 CVE: CVE-2024-41062
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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This fixes the following deadlock introduced by 39a92a55be13 ("bluetooth/l2cap: sync sock recv cb and release")
============================================ WARNING: possible recursive locking detected 6.10.0-rc3-g4029dba6b6f1 #6823 Not tainted -------------------------------------------- kworker/u5:0/35 is trying to acquire lock: ffff888002ec2510 (&chan->lock#2/1){+.+.}-{3:3}, at: l2cap_sock_recv_cb+0x44/0x1e0
but task is already holding lock: ffff888002ec2510 (&chan->lock#2/1){+.+.}-{3:3}, at: l2cap_get_chan_by_scid+0xaf/0xd0
other info that might help us debug this: Possible unsafe locking scenario:
CPU0 ---- lock(&chan->lock#2/1); lock(&chan->lock#2/1);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by kworker/u5:0/35: #0: ffff888002b8a940 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work+0x750/0x930 #1: ffff888002c67dd0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x44e/0x930 #2: ffff888002ec2510 (&chan->lock#2/1){+.+.}-{3:3}, at: l2cap_get_chan_by_scid+0xaf/0xd0
To fix the original problem this introduces l2cap_chan_lock at l2cap_conless_channel to ensure that l2cap_sock_recv_cb is called with chan->lock held.
Fixes: 89e856e124f9 ("bluetooth/l2cap: sync sock recv cb and release") Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com
Conflicts: net/bluetooth/hci_core.c net/bluetooth/l2cap_sock.c [[The conflict occurs because the commit 89e856e124f9("bluetooth/l2cap: sync sock recv cb and release") is not merged] Signed-off-by: Zhengchao Shao shaozhengchao@huawei.com --- net/bluetooth/hci_core.c | 72 ++++++++++---------------------------- net/bluetooth/l2cap_core.c | 3 ++ net/bluetooth/l2cap_sock.c | 12 +------ 3 files changed, 22 insertions(+), 65 deletions(-)
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 18aae3d8b59d..350cbb27356a 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -994,50 +994,6 @@ static int __hci_unconf_init(struct hci_dev *hdev) return 0; }
-static int hci_scan_req(struct hci_request *req, unsigned long opt) -{ - __u8 scan = opt; - - BT_DBG("%s %x", req->hdev->name, scan); - - /* Inquiry and Page scans */ - hci_req_add(req, HCI_OP_WRITE_SCAN_ENABLE, 1, &scan); - return 0; -} - -static int hci_auth_req(struct hci_request *req, unsigned long opt) -{ - __u8 auth = opt; - - BT_DBG("%s %x", req->hdev->name, auth); - - /* Authentication */ - hci_req_add(req, HCI_OP_WRITE_AUTH_ENABLE, 1, &auth); - return 0; -} - -static int hci_encrypt_req(struct hci_request *req, unsigned long opt) -{ - __u8 encrypt = opt; - - BT_DBG("%s %x", req->hdev->name, encrypt); - - /* Encryption */ - hci_req_add(req, HCI_OP_WRITE_ENCRYPT_MODE, 1, &encrypt); - return 0; -} - -static int hci_linkpol_req(struct hci_request *req, unsigned long opt) -{ - __le16 policy = cpu_to_le16(opt); - - BT_DBG("%s %x", req->hdev->name, policy); - - /* Default link policy */ - hci_req_add(req, HCI_OP_WRITE_DEF_LINK_POLICY, 2, &policy); - return 0; -} - /* Get HCI device by index. * Device is held on return. */ struct hci_dev *hci_dev_get(int index) @@ -2000,6 +1956,7 @@ int hci_dev_cmd(unsigned int cmd, void __user *arg) { struct hci_dev *hdev; struct hci_dev_req dr; + __le16 policy; int err = 0;
if (copy_from_user(&dr, arg, sizeof(dr))) @@ -2031,8 +1988,8 @@ int hci_dev_cmd(unsigned int cmd, void __user *arg)
switch (cmd) { case HCISETAUTH: - err = hci_req_sync(hdev, hci_auth_req, dr.dev_opt, - HCI_INIT_TIMEOUT, NULL); + err = __hci_cmd_sync_status(hdev, HCI_OP_WRITE_AUTH_ENABLE, + 1, &dr.dev_opt, HCI_CMD_TIMEOUT); break;
case HCISETENCRYPT: @@ -2043,19 +2000,23 @@ int hci_dev_cmd(unsigned int cmd, void __user *arg)
if (!test_bit(HCI_AUTH, &hdev->flags)) { /* Auth must be enabled first */ - err = hci_req_sync(hdev, hci_auth_req, dr.dev_opt, - HCI_INIT_TIMEOUT, NULL); + err = __hci_cmd_sync_status(hdev, + HCI_OP_WRITE_AUTH_ENABLE, + 1, &dr.dev_opt, + HCI_CMD_TIMEOUT); if (err) break; }
- err = hci_req_sync(hdev, hci_encrypt_req, dr.dev_opt, - HCI_INIT_TIMEOUT, NULL); + err = __hci_cmd_sync_status(hdev, HCI_OP_WRITE_ENCRYPT_MODE, + 1, &dr.dev_opt, + HCI_CMD_TIMEOUT); break;
case HCISETSCAN: - err = hci_req_sync(hdev, hci_scan_req, dr.dev_opt, - HCI_INIT_TIMEOUT, NULL); + err = __hci_cmd_sync_status(hdev, HCI_OP_WRITE_SCAN_ENABLE, + 1, &dr.dev_opt, + HCI_CMD_TIMEOUT);
/* Ensure that the connectable and discoverable states * get correctly modified as this was a non-mgmt change. @@ -2065,8 +2026,11 @@ int hci_dev_cmd(unsigned int cmd, void __user *arg) break;
case HCISETLINKPOL: - err = hci_req_sync(hdev, hci_linkpol_req, dr.dev_opt, - HCI_INIT_TIMEOUT, NULL); + policy = cpu_to_le16(dr.dev_opt); + + err = __hci_cmd_sync_status(hdev, HCI_OP_WRITE_DEF_LINK_POLICY, + 2, &policy, + HCI_CMD_TIMEOUT); break;
case HCISETLINKMODE: diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index ba38af07b556..6d588cd4c699 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -7757,6 +7757,8 @@ static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm,
BT_DBG("chan %p, len %d", chan, skb->len);
+ l2cap_chan_lock(chan); + if (chan->state != BT_BOUND && chan->state != BT_CONNECTED) goto drop;
@@ -7773,6 +7775,7 @@ static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm, }
drop: + l2cap_chan_unlock(chan); l2cap_chan_put(chan); free_skb: kfree_skb(skb); diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 409475da9283..69ab89a60eaa 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1487,17 +1487,9 @@ static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) struct sock *sk; int err;
- /* To avoid race with sock_release, a chan lock needs to be added here - * to synchronize the sock. - */ - l2cap_chan_hold(chan); - l2cap_chan_lock(chan); sk = chan->data; - if (!sk) { - l2cap_chan_unlock(chan); - l2cap_chan_put(chan); + if (!sk) return -ENXIO; - }
lock_sock(sk);
@@ -1535,8 +1527,6 @@ static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
done: release_sock(sk); - l2cap_chan_unlock(chan); - l2cap_chan_put(chan);
return err; }