Eulgyu Kim

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** A use-after-free issue exists in the Linux kernel BPF reuseport program handling. When a UDP reuseport group uses a cBPF program and that program is replaced or detached via the `setsockopt()` path (specifically through `reuseport attach prog()` or `reuseport detach prog()`), the function `sk reuseport prog free()` is called. Because cBPF programs are freed immediately by `bpf release orig filter()` and `bpf prog free()` without waiting for RCU (Read-Copy-Update) readers to complete, a race condition occurs if another thread is simultaneously sending a UDP packet to the group. This can lead to a vmalloc-out-of-bounds read in the `reuseport select sock()` function. **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** A race condition exists in the `mptcp pm nl flush addrs doit()` function within the Linux kernel’s MPTCP implementation. This issue stems from the use of `list splice init()` which is not RCU ready, leading to potential crashes reported by syzbot and Eulgyu Kim in functions such as `mptcp pm nl get local id()` and `mptcp pm nl is backup()`. The root cause is the improper use of `list splice init rcu()` while holding a spinlock. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.