UBUNTU-CVE-2025-40255
In the Linux kernel, the following vulnerability has been resolved: net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower() The ethtool tsconfig Netlink path can trigger a null pointer dereference. A call chain such as: tsconfig_prepare_data() -> dev_get_hwtstamp_phylib() -> vlan_hwtstamp_get() -> generic_hwtstamp_get_lower() -> generic_hwtstamp_ioctl_lower() results in generic_hwtstamp_ioctl_lower() being called with kernel_cfg->ifr as NULL. The generic_hwtstamp_ioctl_lower() function does not expect a NULL ifr and dereferences it, leading to a system crash. Fix this by adding a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL.
02 / AFFECTED SOFTWARE
Affected packages
12 explicit affected versions
11 explicit affected versions
50 explicit affected versions
6 explicit affected versions
19 explicit affected versions
10 explicit affected versions
6 explicit affected versions
24 explicit affected versions
10 explicit affected versions
26 explicit affected versions
7 explicit affected versions
13 explicit affected versions
35 explicit affected versions
18 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
1 explicit affected versions
21 explicit affected versions
16 explicit affected versions
10 explicit affected versions
13 explicit affected versions
8 explicit affected versions
7 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
2 explicit affected versions
12 explicit affected versions
16 explicit affected versions
10 explicit affected versions
10 explicit affected versions
37 explicit affected versions
2 explicit affected versions
13 explicit affected versions
3 explicit affected versions
10 explicit affected versions
11 explicit affected versions
26 explicit affected versions
13 explicit affected versions
29 explicit affected versions
13 explicit affected versions
12 explicit affected versions
1 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
11 explicit affected versions
5 explicit affected versions
12 explicit affected versions
2 explicit affected versions
7 explicit affected versions
12 explicit affected versions
1 explicit affected versions
9 explicit affected versions
5 explicit affected versions
10 explicit affected versions
26 explicit affected versions
11 explicit affected versions
2 explicit affected versions
13 explicit affected versions
16 explicit affected versions
3 explicit affected versions
7 explicit affected versions
8 explicit affected versions
51 explicit affected versions
9 explicit affected versions
18 explicit affected versions
12 explicit affected versions
3 explicit affected versions
27 explicit affected versions
8 explicit affected versions
5 explicit affected versions
8 explicit affected versions
10 explicit affected versions
7 explicit affected versions
13 explicit affected versions
13 explicit affected versions
7 explicit affected versions
8 explicit affected versions
10 explicit affected versions
12 explicit affected versions
9 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
10 explicit affected versions
11 explicit affected versions
7 explicit affected versions
7 explicit affected versions
4 explicit affected versions
1 explicit affected versions
1 explicit affected versions
13 explicit affected versions
43 explicit affected versions
8 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
7 explicit affected versions
11 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower() The ethtool tsconfig Netlink path can trigger a null pointer dereference. A call chain such as: tsconfig_prepare_data() -> dev_get_hwtstamp_phylib() -> vlan_hwtstamp_get() -> generic_hwtstamp_get_lower() -> generic_hwtstamp_ioctl_lower() results in generic_hwtstamp_ioctl_lower() being called with kernel_cfg->ifr as NULL. The generic_hwtstamp_ioctl_lower() function does not expect a NULL ifr and dereferences it, leading to a system crash. Fix this by adding a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/f796a8dec9beafcc0f6f0d3478ed685a15c5e062
- https://git.kernel.org/stable/c/8817f816ae41908e9625c0770c4af0dcdcc01238
- https://git.kernel.org/stable/c/f796a8dec9beafcc0f6f0d3478ed685a15c5e062
- https://ubuntu.com/security/CVE-2025-40255
- https://ubuntu.com/security/notices/USN-8094-1
- https://ubuntu.com/security/notices/USN-8094-2
- https://ubuntu.com/security/notices/USN-8094-3
- https://ubuntu.com/security/notices/USN-8094-4
- https://ubuntu.com/security/notices/USN-8094-5
- https://ubuntu.com/security/notices/USN-8152-1
- https://www.cve.org/CVERecord?id=CVE-2025-40255