CVE-2024-26663: tipc: Check the bearer type before calling tipc_udp_nl_bearer_add()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-02 · updated 2026-08-04
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: tipc: Check the bearer type before calling tipc_udp_nl_bearer_add() syzbot reported the following general protection fault [1]: general protection fault, probably for non-canonical address 0xdffffc0000000010: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000080-0x0000000000000087] ... RIP: 0010:tipc_udp_is_known_peer+0x9c/0x250 net/tipc/udp_media.c:291 ... Call Trace: <TASK> tipc_udp_nl_bearer_add+0x212/0x2f0 net/tipc/udp_media.c:646 tipc_nl_bearer_add+0x21e/0x360 net/tipc/bearer.c:1089 genl_family_rcv_msg_doit+0x1fc/0x2e0 net/netlink/genetlink.c:972 genl_family_rcv_msg net/netlink/genetlink.c:1052 [inline] genl_rcv_msg+0x561/0x800 net/netlink/genetlink.c:1067 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2544 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1076 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x53b/0x810 net/netlink/af_netlink.c:1367 netlink_sendmsg+0x8b7/0xd70 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2584 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2638 __sys_sendmsg+0x117/0x1e0 net/socket.c:2667 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b The cause of this issue is that when tipc_nl_bearer_add() is called with the TIPC_NLA_BEARER_UDP_OPTS attribute, tipc_udp_nl_bearer_add() is called even if the bearer is not UDP. tipc_udp_is_known_peer() called by tipc_udp_nl_bearer_add() assumes that the media_ptr field of the tipc_bearer has an udp_bearer type object, so the function goes crazy for non-UDP bearers. This patch fixes the issue by checking the bearer type before calling tipc_udp_nl_bearer_add() in tipc_nl_bearer_add().

Affected products

Debian Linux: 10.0
Linux kernel: from 4.9 before 4.19.307; from 4.20 before 5.4.269; from 5.5 before 5.10.210; from 5.11 before 5.15.149; from 5.16 before 6.1.78; from 6.2 before 6.6.17 — fixed in 4.19.307, 5.10.210, 5.15.149, 5.4.269, 6.1.78, 6.6.17

How to fix

Upgrade to a fixed version: Linux kernel 4.19.307, 5.10.210, 5.15.149, 5.4.269. Check the vendor advisory for mitigations.

References

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