CVE-2026-98098

Description

In the Linux kernel, the following vulnerability has been resolved: tipc: fix NULL deref in tipc_named_node_up() on empty publication list User-space applications can bind a large number of service addresses to one or more sockets. Each binding of a local-scope service address inserts one entry (publication) into the TIPC name table. If the number of these publications exceeds TIPC_MAX_PUBL (65535), protocol service types (such as node state and link state) are no longer inserted into the name table. This causes two issues: 1. User-space applications subscribing to node or link up/down events stop receiving notifications. 2. A NULL pointer dereference can occur: BUG: kernel NULL pointer dereference, address: 00000000000000d0 ... CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 7.2.0-rc4-default+ #5 PREEMPT(full) ... RIP: 0010:tipc_named_node_up (./include/linux/skbuff.h:2251 net/tipc/name_distr.c:195 net/tipc/name_distr.c:221) ... Call Trace: <IRQ> tipc_node_write_unlock (net/tipc/node.c:428) tipc_rcv (net/tipc/node.c:934 net/tipc/node.c:2189) tipc_udp_recv (net/tipc/udp_media.c:389) Thread 1 (tipc_net_finalize) | Thread 2 (named_distribute) -----------------------------|----------------------------- | ... | list_for_each_entry(publ, pls, binding_node) { | ... | __skb_queue_tail(list, skb); | ... | } | ... | hdr = buf_msg(skb_peek_tail(list)); ... | tipc_nametbl_publish(); | If 'tipc_nametbl_publish()' (Thread 1) fails because the number of local publications reaches TIPC_MAX_PUBL, list (Thread 2) will be empty. As a result, NULL is passed to 'buf_msg()', leading to a NULL pointer dereference. Fix these issues by allowing protocol service types (node state, link state, and topology server) to be inserted into the name table unconditionally. This ensures that users subscribing to these types always receive notifications. In addition, the maximum number of local user publications is reduced to (TIPC_MAX_PUBL - 1). This ensures that the maximum bulk size calculated in tipc_link_set_queue_limits() remains valid.

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EPSS — Exploit Prediction

0.0018

Probability of exploitation

0.07%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/68619f965329d2f7b113a3d5811aa23198f39105 https://git.kernel.org/stable/c/ad805326d874062f8bc72a94884f86046148cde3 https://git.kernel.org/stable/c/b3b76e9f4f2476f1135b2ba7743a821db4a0df4b https://git.kernel.org/stable/c/d0d82f1214f321143c5dbc2e48e4a4e6c4226895

Frequently Asked Questions

What is CVE-2026-98098? +

In the Linux kernel, the following vulnerability has been resolved: tipc: fix NULL deref in tipc_named_node_up() on empty publication list User-space applications can bind a large number of service addresses to one or more sockets. Each binding of a local-scope service address inserts one entry (publication) into the TIPC name table. If the number of these publications exceeds TIPC_MAX_PUBL (65535), protocol service types (such as node state and link state) are no longer inserted into the name table. This causes two issues: 1. User-space applications subscribing to node or link up/down events stop receiving notifications. 2. A NULL pointer dereference can occur: BUG: kernel NULL pointer dereference, address: 00000000000000d0 ... CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 7.2.0-rc4-default+ #5 PREEMPT(full) ... RIP: 0010:tipc_named_node_up (./include/linux/skbuff.h:2251 net/tipc/name_distr.c:195 net/tipc/name_distr.c:221) ... Call Trace: <IRQ> tipc_node_write_unlock (net/tipc/node.c:428) tipc_rcv (net/tipc/node.c:934 net/tipc/node.c:2189) tipc_udp_recv (net/tipc/udp_media.c:389) Thread 1 (tipc_net_finalize) | Thread 2 (named_distribute) -----------------------------|----------------------------- | ... | list_for_each_entry(publ, pls, binding_node) { | ... | __skb_queue_tail(list, skb); | ... | } | ... | hdr = buf_msg(skb_peek_tail(list)); ... | tipc_nametbl_publish(); | If 'tipc_nametbl_publish()' (Thread 1) fails because the number of local publications reaches TIPC_MAX_PUBL, list (Thread 2) will be empty. As a result, NULL is passed to 'buf_msg()', leading to a NULL pointer dereference. Fix these issues by allowing protocol service types (node state, link state, and topology server) to be inserted into the name table unconditionally. This ensures that users subscribing to these types always receive notifications. In addition, the maximum number of local user publications is reduced to (TIPC_MAX_PUBL - 1). This ensures that the maximum bulk size calculated in tipc_link_set_queue_limits() remains valid.

How do I check if I'm vulnerable to CVE-2026-98098? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.