CVE-2025-38006 net: mctp: Don't access ifa_index when missing
A local attacker can trigger uninitialized memory access in the Linux kernel MCTP subsystem, potentially leaking sensitive kernel memory.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-38006?
CVE-2025-38006 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: mctp: Don't access ifa_index when missing
In mctp_dump_addrinfo, ifa_index can be used to filter interfaces, but only when the struct ifaddrmsg is provided. Otherwise it will be comparing to uninitialised memory - reproducible in the syzkaller case from dhcpd, or busybox "ip addr show".
The kernel MCTP implementation has always filtered by ifa_index, so existing userspace programs expecting to dump MCTP addresses must already be passing a valid ifa_index value (either 0 or a real index).
BUG: KMSAN: uninit-value in mctp_dump_addrinfo+0x208/0xac0 net/mctp/device.c:128 mctp_dump_addrinfo+0x208/0xac0 net/mctp/device.c:128 rtnl_dump_all+0x3ec/0x5b0 net/core/rtnetlink.c:4380 rtnl_dumpit+0xd5/0x2f0 net/core/rtnetlink.c:6824 netlink_dump+0x97b/0x1690 net/netlink/af_netlink.c:2309
Weakness: CWE-908
Which versions are affected by CVE-2025-38006?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-38006?
Apply the vendor's patch.
Is CVE-2025-38006 being exploited?
There is no known exploitation of CVE-2025-38006 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-38006, DEBIAN-CVE-2025-38006, GHSA-q3wc-vx42-5j3g, ROOT-OS-DEBIAN-12-CVE-2025-38006, ROOT-OS-UBUNTU-2204-CVE-2025-38006, ROOT-OS-UBUNTU-2404-CVE-2025-38006 and 1 more.