CVE-2024-36968: Linux kernel · Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.6 High · fixed in 4.4.0-1139.145 : patch Linux kernel soon.
Data as of 28 Oct 2026, 10:59 UTC
- Patch
- Available – fixed in 4.4.0-1139.145, 4.15.0-1184.199~14.04.1, 4.4.0-262.296~14.04.1 +91
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 Jun 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6949-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6955-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-3 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init() l2cap_le_flowctl_init() can cause both div-by-zero and an integer overflow since hdev->le_mtu may not fall in the valid range. Move MTU from hci_dev to hci_conn to validate MTU and stop the connection process earlier if MTU is invalid. Also, add a missing validation in read_buffer_size() and make it return an error value if the validation fails. Now hci_conn_add() returns ERR_PTR() as it can fail due to the both a kzalloc failure and invalid MTU value. divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: G W 6.9.0-rc5+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: hci0 hci_rx_work RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547 Code: e8 17 17 0c 00 66 41 89 9f 84 00 00 00 bf 01 00 00 00 41 b8 02 00 00 00 4c 89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42 RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246 RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff88810bc0f7c0 RDI: ffffc90002dcb66f RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa R10: 0084000000ffaaaa R11: 0000000000000000 R12: ffff88810d65a084 R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000 FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> l2cap_le_connect_req net/bluetooth/l2cap_core.c:4902 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [inline] l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c:6809 l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506 hci_acldata_packet net/bluetooth/hci_core.c:3939 [inline] hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335 worker_thread+0x926/0xe70 kernel/workqueue.c:3416 kthread+0x2e3/0x380 kernel/kthread.c:388 ret_from_fork+0x5c/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]---
References
- ubuntu.com/security/CVE-2024-36968 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-36968 (opens in a new tab)
- git.kernel.org/linus/a5b862c6a221459d54e494e88965b48dcfa6cc44 (opens in a new tab)
- git.kernel.org/stable/c/ad3f7986c5a0f82b8b66a0afe1cc1f5421e1d674 (opens in a new tab)
- git.kernel.org/stable/c/dfece2b4e3759759b2bdfac2cd6d0ee9fbf055f3 (opens in a new tab)
- git.kernel.org/stable/c/d2b2f7d3936dc5990549bc36ab7ac7ac37f22c30 (opens in a new tab)
- git.kernel.org/stable/c/a5b862c6a221459d54e494e88965b48dcfa6cc44 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6955-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-5 (opens in a new tab)