CVE-2023-53517
Linux Kernel vulnerability
- Published1 Oct 2025
Description
In the Linux kernel, the following vulnerability has been resolved: tipc: do not update mtu if msg_max is too small in mtu negotiation When doing link mtu negotiation, a malicious peer may send Activate msg with a very small mtu, e.g. 4 in Shuang's testing, without checking for the minimum mtu, l->mtu will be set to 4 in tipc_link_proto_rcv(), then n->links[bearer_id].mtu is set to 4294967228, which is a overflow of '4 - INT_H_SIZE - EMSG_OVERHEAD' in tipc_link_mss(). With tipc_link.mtu = 4, tipc_link_xmit() kept printing the warning: tipc: Too large msg, purging xmit list 1 5 0 40 4! tipc: Too large msg, purging xmit list 1 15 0 60 4! And with tipc_link_entry.mtu 4294967228, a huge skb was allocated in named_distribute(), and when purging it in tipc_link_xmit(), a crash was even caused: general protection fault, probably for non-canonical address 0x2100001011000dd: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Not tainted 6.3.0.neta #19 RIP: 0010:kfree_skb_list_reason+0x7e/0x1f0 Call Trace: <IRQ> skb_release_data+0xf9/0x1d0 kfree_skb_reason+0x40/0x100 tipc_link_xmit+0x57a/0x740 [tipc] tipc_node_xmit+0x16c/0x5c0 [tipc] tipc_named_node_up+0x27f/0x2c0 [tipc] tipc_node_write_unlock+0x149/0x170 [tipc] tipc_rcv+0x608/0x740 [tipc] tipc_udp_recv+0xdc/0x1f0 [tipc] udp_queue_rcv_one_skb+0x33e/0x620 udp_unicast_rcv_skb.isra.72+0x75/0x90 __udp4_lib_rcv+0x56d/0xc20 ip_protocol_deliver_rcu+0x100/0x2d0 This patch fixes it by checking the new mtu against tipc_bearer_min_mtu(), and not updating mtu if it is too small.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected products
Remediation
- https://git.kernel.org/stable/c/1dd7ae5e0cf5a56e513f7ab7ab9570b7496281d2
- https://git.kernel.org/stable/c/259683001d7e879fea4b42084fb6560dd9408a7e
- https://git.kernel.org/stable/c/2bd4ff4ffb92113f8acd04dbaed83269172c24b4
- https://git.kernel.org/stable/c/56077b56cd3fb78e1c8619e29581ba25a5c55e86
- https://git.kernel.org/stable/c/575e84d90a74c0b091b3417ba763ebb237aa0a8c
References
- https://git.kernel.org/stable/c/1dd7ae5e0cf5a56e513f7ab7ab9570b7496281d2
- https://git.kernel.org/stable/c/259683001d7e879fea4b42084fb6560dd9408a7e
- https://git.kernel.org/stable/c/2bd4ff4ffb92113f8acd04dbaed83269172c24b4
- https://git.kernel.org/stable/c/56077b56cd3fb78e1c8619e29581ba25a5c55e86
- https://git.kernel.org/stable/c/575e84d90a74c0b091b3417ba763ebb237aa0a8c
Frequently asked
Is CVE-2023-53517 being actively exploited?
CVE-2023-53517 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.30%.
How severe is CVE-2023-53517?
CVE-2023-53517 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.30% probability of exploitation.
Which products are affected by CVE-2023-53517?
Affected products include Linux Kernel.
How do I fix CVE-2023-53517?
Upgrade affected software to a fixed version, for example Linux Kernel 5.10.181 or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2023-53517 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.