{"cve":"CVE-2024-36009","nvd":{"published":"2024-05-20T10:15:14.773","modified":"2026-08-04T11:18:21.710","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nax25: Fix netdev refcount issue\n\nThe dev_tracker is added to ax25_cb in ax25_bind(). When the\nax25 device is detaching, the dev_tracker of ax25_cb should be\ndeallocated in ax25_kill_by_device() instead of the dev_tracker\nof ax25_dev. The log reported by ref_tracker is shown below:\n\n[   80.884935] ref_tracker: reference already released.\n[   80.885150] ref_tracker: allocated in:\n[   80.885349]  ax25_dev_device_up+0x105/0x540\n[   80.885730]  ax25_device_event+0xa4/0x420\n[   80.885730]  notifier_call_chain+0xc9/0x1e0\n[   80.885730]  __dev_notify_flags+0x138/0x280\n[   80.885730]  dev_change_flags+0xd7/0x180\n[   80.885730]  dev_ifsioc+0x6a9/0xa30\n[   80.885730]  dev_ioctl+0x4d8/0xd90\n[   80.885730]  sock_do_ioctl+0x1c2/0x2d0\n[   80.885730]  sock_ioctl+0x38b/0x4f0\n[   80.885730]  __se_sys_ioctl+0xad/0xf0\n[   80.885730]  do_syscall_64+0xc4/0x1b0\n[   80.885730]  entry_SYSCALL_64_after_hwframe+0x67/0x6f\n[   80.885730] ref_tracker: freed in:\n[   80.885730]  ax25_device_event+0x272/0x420\n[   80.885730]  notifier_call_chain+0xc9/0x1e0\n[   80.885730]  dev_close_many+0x272/0x370\n[   80.885730]  unregister_netdevice_many_notify+0x3b5/0x1180\n[   80.885730]  unregister_netdev+0xcf/0x120\n[   80.885730]  sixpack_close+0x11f/0x1b0\n[   80.885730]  tty_ldisc_kill+0xcb/0x190\n[   80.885730]  tty_ldisc_hangup+0x338/0x3d0\n[   80.885730]  __tty_hangup+0x504/0x740\n[   80.885730]  tty_release+0x46e/0xd80\n[   80.885730]  __fput+0x37f/0x770\n[   80.885730]  __x64_sys_close+0x7b/0xb0\n[   80.885730]  do_syscall_64+0xc4/0x1b0\n[   80.885730]  entry_SYSCALL_64_after_hwframe+0x67/0x6f\n[   80.893739] ------------[ cut here ]------------\n[   80.894030] WARNING: CPU: 2 PID: 140 at lib/ref_tracker.c:255 ref_tracker_free+0x47b/0x6b0\n[   80.894297] Modules linked in:\n[   80.894929] CPU: 2 PID: 140 Comm: ax25_conn_rel_6 Not tainted 6.9.0-rc4-g8cd26fd90c1a #11\n[   80.895190] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qem4\n[   80.895514] RIP: 0010:ref_tracker_free+0x47b/0x6b0\n[   80.895808] Code: 83 c5 18 4c 89 eb 48 c1 eb 03 8a 04 13 84 c0 0f 85 df 01 00 00 41 83 7d 00 00 75 4b 4c 89 ff 9\n[   80.896171] RSP: 0018:ffff888009edf8c0 EFLAGS: 00000286\n[   80.896339] RAX: 1ffff1100141ac00 RBX: 1ffff1100149463b RCX: dffffc0000000000\n[   80.896502] RDX: 0000000000000001 RSI: 0000000000000246 RDI: ffff88800a0d6518\n[   80.896925] RBP: ffff888009edf9b0 R08: ffff88806d3288d3 R09: 1ffff1100da6511a\n[   80.897212] R10: dffffc0000000000 R11: ffffed100da6511b R12: ffff88800a4a31d4\n[   80.897859] R13: ffff88800a4a31d8 R14: dffffc0000000000 R15: ffff88800a0d6518\n[   80.898279] FS:  00007fd88b7fe700(0000) GS:ffff88806d300000(0000) knlGS:0000000000000000\n[   80.899436] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[   80.900181] CR2: 00007fd88c001d48 CR3: 000000000993e000 CR4: 00000000000006f0\n...\n[   80.935774] ref_tracker: sp%d@000000000bb9df3d has 1/1 users at\n[   80.935774]      ax25_bind+0x424/0x4e0\n[   80.935774]      __sys_bind+0x1d9/0x270\n[   80.935774]      __x64_sys_bind+0x75/0x80\n[   80.935774]      do_syscall_64+0xc4/0x1b0\n[   80.935774]      entry_SYSCALL_64_after_hwframe+0x67/0x6f\n\nChange ax25_dev->dev_tracker to the dev_tracker of ax25_cb\nin order to mitigate the bug.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/0d14f104027e30720582448706c7d6b43065c851","https://git.kernel.org/stable/c/467324bcfe1a31ec65d0cf4aa59421d6b7a7d52b","https://git.kernel.org/stable/c/4fee8fa86a15d7790268eea458b1aec69c695530","https://git.kernel.org/stable/c/c42b073d9af4a5329b25b17390c63ab3847f30e8","http://www.openwall.com/lists/oss-security/2024/05/30/1"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2024-36009","score":0.00235,"percentile":0.14507,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}