Cong Wang

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** A potential NULL pointer dereference has been resolved in the Linux kernel. The issue occurs when `sockfd lookup()` fails, causing `gtp encap enable socket()` to return a NULL pointer. However, its callers only check for error pointers, thus missing the NULL pointer case. The fix involves returning an error pointer with the error code carried from `sockfd lookup()`. This bug was found during code inspection. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** The issue arises from the `tcf skbmod act()` function assuming that packets use Ethernet as their L2 protocol, which is not always the case. This can lead to silent corruption of packets when using non-Ethernet protocols, such as CAN devices. The problem occurs when the `skbmod` action is performed on non-Ethernet packets. To demonstrate this, an example is given using CAN devices, where the `ip link add` and `tc qdisc add` commands are used to set up a network interface and traffic control, respectively. The `matchall action skbmod swap mac` command is then used to swap the MAC addresses of packets, which silently corrupts them. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** Linux kernel versions through 4.3.3 **Description** The issue is related to the networking implementation in the Linux kernel, which does not properly validate protocol identifiers for certain protocol families. This can be exploited by local users to cause a denial of service, resulting in a system crash due to a NULL function pointer dereference. It is also possible for attackers to gain privileges by executing a crafted SOCK RAW application, leveraging CLONE NEWUSER support. The vulnerability may allow an attacker to access confidential data, compromise its integrity, and cause a denial of service. **Recommendations** For Linux kernel versions through 4.3.3, update to a version newer than 4.3.3 to resolve the issue. At the moment, there is no information about additional mitigation measures for this vulnerability.