CVE-2024-26834 netfilter: nft_flow_offload: release dst in case direct xmit path is used
A memory leak in the Linux kernel netfilter flow offload module can lead to resource exhaustion and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-26834?
CVE-2024-26834 is a high-severity memory corruption vulnerability in Linux kernel, published on 17 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_flow_offload: release dst in case direct xmit path is used
Direct xmit does not use it since it calls dev_queue_xmit() to send packets, hence it calls dst_release().
kmemleak reports:
unreferenced object 0xffff88814f440900 (size 184): comm "softirq", pid 0, jiffies 4294951896 hex dump (first 32 bytes): 00 60 5b 04 81 88 ff ff 00 e6 e8 82 ff ff ff ff .`[............. 21 0b 50 82 ff ff ff ff 00 00 00 00 00 00 00 00 !.P............. backtrace (crc cb2bf5d6): [<000000003ee17107>] kmem_cache_alloc+0x286/0x340 [<0000000021a5de2c>] dst_alloc+0x43/0xb0 [<00000000f0671159>] rt_dst_alloc+0x2e/0x190 [<00000000fe5092c9>] __mkroute_output+0x244/0x980 [<000000005fb96fb0>] ip_route_output_flow+0xc0/0x160 [<0000000045367433>] nf_ip_route+0xf/0x30 [<0000000085da1d8e>] nf_route+0x2d/0x60 [<00000000d1ecd1cb>] nft_flow_route+0x171/0x6a0 [nft_flow_offload] [<00000000d9b2fb60>] nft_flow_offload_eval+0x4e8/0x700 [nft_flow_offload] [<000000009f447dbb>] expr_call_ops_eval+0x53/0x330 [nf_tables] [<00000000072e1be6>] nft_do_chain+0x17c/0x840 [nf_tables] [<00000000d0551029>] nft_do_chain_inet+0xa1/0x210 [nf_tables] [<0000000097c9d5c6>] nf_hook_slow+0x5b/0x160 [<0000000005eccab1>] ip_forward+0x8b6/0x9b0 [<00000000553a269b>] ip_rcv+0x221/0x230 [<00000000412872e5>] __netif_receive_skb_one_core+0xfe/0x110
Which versions are affected by CVE-2024-26834?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-26834?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2024-26834 being exploited?
There is no known exploitation of CVE-2024-26834 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-26834, DEBIAN-CVE-2024-26834, GHSA-w6vh-9g8v-hhwg, UBUNTU-CVE-2024-26834.