CVE-2025-38572 ipv6: reject malicious packets in ipv6_gso_segment()
A crafted IPv6 packet with long extension headers causes an integer overflow in the Linux kernel, leading to a system crash.
- 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-2025-38572?
CVE-2025-38572 is a high-severity vulnerability in Debian Debian Linux, published on 19 Aug 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:
ipv6: reject malicious packets in ipv6_gso_segment()
syzbot was able to craft a packet with very long IPv6 extension headers leading to an overflow of skb->transport_header.
This 16bit field has a limited range.
Add skb_reset_transport_header_careful() helper and use it from ipv6_gso_segment()
WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 skb_reset_transport_header include/linux/skbuff.h:3032 [inline] WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151 Modules linked in: CPU: 0 UID: 0 PID: 5871 Comm: syz-executor211 Not tainted 6.16.0-rc6-syzkaller-g7abc678e3084 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:skb_reset_transport_header include/linux/skbuff.h:3032 [inline] RIP: 0010:ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151 Call Trace: <TASK> skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53 nsh_gso_segment+0x54a/0xe10 net/nsh/nsh.c:110 skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53 __skb_gso_segment+0x342/0x510 net/core/gso.c:124 skb_gso_segment include/net/gso.h:83 [inline] validate_xmit_skb+0x857/0x11b0 net/core/dev.c:3950 validate_xmit_skb_list+0x84/0x120 net/core/dev.c:4000 sch_direct_xmit+0xd3/0x4b0 net/sched/sch_generic.c:329 __dev_xmit_skb net/core/dev.c:4102 [inline] __dev_queue_xmit+0x17b6/0x3a70 net/core/dev.c:4679
Which versions are affected by CVE-2025-38572?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38572?
Apply the vendor's patch.
Is CVE-2025-38572 being exploited?
There is no known exploitation of CVE-2025-38572 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-66527, AZL-73854, BELL-CVE-2025-38572, DEBIAN-CVE-2025-38572, GHSA-j327-57v5-q43v, ROOT-OS-DEBIAN-11-CVE-2025-38572 and 5 more.