CVE-2025-38441 netfilter: flowtable: account for Ethernet header in nf_flow_pppoe_proto()
A missing Ethernet header check in the Linux kernel netfilter flowtable allows attackers to read uninitialized memory, potentially leaking sensitive kernel data.
- 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-2025-38441?
CVE-2025-38441 is a medium-severity vulnerability in Debian Debian Linux, published on 25 Jul 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:
netfilter: flowtable: account for Ethernet header in nf_flow_pppoe_proto()
syzbot found a potential access to uninit-value in nf_flow_pppoe_proto()
Blamed commit forgot the Ethernet header.
BUG: KMSAN: uninit-value in nf_flow_offload_inet_hook+0x7e4/0x940 net/netfilter/nf_flow_table_inet.c:27 nf_flow_offload_inet_hook+0x7e4/0x940 net/netfilter/nf_flow_table_inet.c:27 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xe1/0x3d0 net/netfilter/core.c:623 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline] nf_ingress net/core/dev.c:5742 [inline] __netif_receive_skb_core+0x4aff/0x70c0 net/core/dev.c:5837 __netif_receive_skb_one_core net/core/dev.c:5975 [inline] __netif_receive_skb+0xcc/0xac0 net/core/dev.c:6090 netif_receive_skb_internal net/core/dev.c:6176 [inline] netif_receive_skb+0x57/0x630 net/core/dev.c:6235 tun_rx_batched+0x1df/0x980 drivers/net/tun.c:1485 tun_get_user+0x4ee0/0x6b40 drivers/net/tun.c:1938 tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1984 new_sync_write fs/read_write.c:593 [inline] vfs_write+0xb4b/0x1580 fs/read_write.c:686 ksys_write fs/read_write.c:738 [inline] __do_sys_write fs/read_write.c:749 [inline]
Weakness: CWE-908
Which versions are affected by CVE-2025-38441?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38441?
Apply the vendor's patch.
Is CVE-2025-38441 being exploited?
There is no known exploitation of CVE-2025-38441 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-72920, BELL-CVE-2025-38441, DEBIAN-CVE-2025-38441, GHSA-h35g-vvhp-7ww4, ROOT-OS-UBUNTU-2204-CVE-2025-38441, ROOT-OS-UBUNTU-2404-CVE-2025-38441 and 1 more.