CVE-2024-57841 net: fix memory leak in tcp_conn_request()
A memory leak in the Linux kernel TCP connection handling allows attackers to exhaust system memory, leading to denial of service.
- 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-2024-57841?
CVE-2024-57841 is a medium-severity denial of service vulnerability in Linux kernel, published on 15 Jan 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: fix memory leak in tcp_conn_request()
If inet_csk_reqsk_queue_hash_add() return false, tcp_conn_request() will return without free the dst memory, which allocated in af_ops->route_req.
Here is the kmemleak stack:
unreferenced object 0xffff8881198631c0 (size 240): comm "softirq", pid 0, jiffies 4299266571 (age 1802.392s) hex dump (first 32 bytes): 00 10 9b 03 81 88 ff ff 80 98 da bc ff ff ff ff ................ 81 55 18 bb ff ff ff ff 00 00 00 00 00 00 00 00 .U.............. backtrace: [<ffffffffb93e8d4c>] kmem_cache_alloc+0x60c/0xa80 [<ffffffffba11b4c5>] dst_alloc+0x55/0x250 [<ffffffffba227bf6>] rt_dst_alloc+0x46/0x1d0 [<ffffffffba23050a>] __mkroute_output+0x29a/0xa50 [<ffffffffba23456b>] ip_route_output_key_hash+0x10b/0x240 [<ffffffffba2346bd>] ip_route_output_flow+0x1d/0x90 [<ffffffffba254855>] inet_csk_route_req+0x2c5/0x500 [<ffffffffba26b331>] tcp_conn_request+0x691/0x12c0 [<ffffffffba27bd08>] tcp_rcv_state_process+0x3c8/0x11b0 [<ffffffffba2965c6>] tcp_v4_do_rcv+0x156/0x3b0 [<ffffffffba299c98>] tcp_v4_rcv+0x1cf8/0x1d80 [<ffffffffba239656>] ip_protocol_deliver_rcu+0xf6/0x360 [<ffffffffba2399a6>] ip_local_deliver_finish+0xe6/0x1e0 [<ffffffffba239b8e>] ip_local_deliver+0xee/0x360 [<ffffffffba239ead>] ip_rcv+0xad/0x2f0 [<ffffffffba110943>] __netif_receive_skb_one_core+0x123/0x140
Call dst_release() to free the dst memory when inet_csk_reqsk_queue_hash_add() return false in tcp_conn_request().
Weakness: CWE-401
Which versions are affected by CVE-2024-57841?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-57841?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-57841 being exploited?
There is no known exploitation of CVE-2024-57841 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-55846, AZL-55869, BELL-CVE-2024-57841, DEBIAN-CVE-2024-57841, GHSA-qxf9-65gj-mxj8, UBUNTU-CVE-2024-57841.