ax25: Fix refcount imbalance on inbound connections
When releasing a socket in ax25_release(), we call netdev_put() to
decrease the refcount on the associated ax.25 device. However, the
execution path for accepting an incoming connection never calls
netdev_hold(). This imbalance leads to refcount errors, and ultimately
to kernel crashes.
A typical call trace for the above situation will start with one of the
following errors:
refcount_t: decrement hit 0; leaking memory.
refcount_t: underflow; use-after-free.
And will then have a trace like:
Call Trace:
<TASK>
? show_regs+0x64/0x70
? __warn+0x83/0x120
? refcount_warn_saturate+0xb2/0x100
? report_bug+0x158/0x190
? prb_read_valid+0x20/0x30
? handle_bug+0x3e/0x70
? exc_invalid_op+0x1c/0x70
? asm_exc_invalid_op+0x1f/0x30
? refcount_warn_saturate+0xb2/0x100
? refcount_warn_saturate+0xb2/0x100
ax25_release+0x2ad/0x360
__sock_release+0x35/0xa0
sock_close+0x19/0x20
[...]
On reboot (or any attempt to remove the interface), the kernel gets
stuck in an infinite loop:
unregister_netdevice: waiting for ax0 to become free. Usage count = 0
This patch corrects these issues by ensuring that we call netdev_hold()
and ax25_dev_hold() for new connections in ax25_accept(). This makes the
logic leading to ax25_accept() match the logic for ax25_bind(): in both
cases we increment the refcount, which is ultimately decremented in
ax25_release().
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4008-1 | linux-6.1 security update |
Debian DSA |
DSA-5731-1 | linux security update |
Ubuntu USN |
USN-6999-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6999-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7004-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7005-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7005-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7008-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7029-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7173-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7173-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7179-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7173-3 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7179-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7179-3 | Linux kernel (GKE) vulnerabilities |
Ubuntu USN |
USN-7179-4 | Linux kernel (Xilinx ZynqMP) vulnerabilities |
Ubuntu USN |
USN-7186-1 | Linux kernel (Intel IoTG) vulnerabilities |
Ubuntu USN |
USN-7186-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7194-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7195-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7195-2 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7332-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7332-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7332-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7342-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7344-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7344-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7413-1 | Linux kernel (IoT) vulnerabilities |
Mon, 03 Nov 2025 22:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 11 Sep 2024 13:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Thu, 29 Aug 2024 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | NVD-CWE-Other | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.10:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.10:rc2:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T20:22:11.559Z
Reserved: 2024-07-12T12:17:45.580Z
Link: CVE-2024-40910
Updated: 2024-08-02T04:39:55.370Z
Status : Modified
Published: 2024-07-12T13:15:14.213
Modified: 2025-11-03T22:17:13.000
Link: CVE-2024-40910
OpenCVE Enrichment
No data.
Debian DLA
Debian DSA
Ubuntu USN