CVE-2023-54236: net/net_failover: fix txq exceeding warning

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-30 · updated 2026-10-28

Description

In the Linux kernel, the following vulnerability has been resolved: net/net_failover: fix txq exceeding warning The failover txq is inited as 16 queues. when a packet is transmitted from the failover device firstly, the failover device will select the queue which is returned from the primary device if the primary device is UP and running. If the primary device txq is bigger than the default 16, it can lead to the following warning: eth0 selects TX queue 18, but real number of TX queues is 16 The warning backtrace is: [ 32.146376] CPU: 18 PID: 9134 Comm: chronyd Tainted: G E 6.2.8-1.el7.centos.x86_64 #1 [ 32.147175] Hardware name: Red Hat KVM, BIOS 1.10.2-3.el7_4.1 04/01/2014 [ 32.147730] Call Trace: [ 32.147971] <TASK> [ 32.148183] dump_stack_lvl+0x48/0x70 [ 32.148514] dump_stack+0x10/0x20 [ 32.148820] netdev_core_pick_tx+0xb1/0xe0 [ 32.149180] __dev_queue_xmit+0x529/0xcf0 [ 32.149533] ? __check_object_size.part.0+0x21c/0x2c0 [ 32.149967] ip_finish_output2+0x278/0x560 [ 32.150327] __ip_finish_output+0x1fe/0x2f0 [ 32.150690] ip_finish_output+0x2a/0xd0 [ 32.151032] ip_output+0x7a/0x110 [ 32.151337] ? __pfx_ip_finish_output+0x10/0x10 [ 32.151733] ip_local_out+0x5e/0x70 [ 32.152054] ip_send_skb+0x19/0x50 [ 32.152366] udp_send_skb.isra.0+0x163/0x3a0 [ 32.152736] udp_sendmsg+0xba8/0xec0 [ 32.153060] ? __folio_memcg_unlock+0x25/0x60 [ 32.153445] ? __pfx_ip_generic_getfrag+0x10/0x10 [ 32.153854] ? sock_has_perm+0x85/0xa0 [ 32.154190] inet_sendmsg+0x6d/0x80 [ 32.154508] ? inet_sendmsg+0x6d/0x80 [ 32.154838] sock_sendmsg+0x62/0x70 [ 32.155152] ____sys_sendmsg+0x134/0x290 [ 32.155499] ___sys_sendmsg+0x81/0xc0 [ 32.155828] ? _get_random_bytes.part.0+0x79/0x1a0 [ 32.156240] ? ip4_datagram_release_cb+0x5f/0x1e0 [ 32.156649] ? get_random_u16+0x69/0xf0 [ 32.156989] ? __fget_light+0xcf/0x110 [ 32.157326] __sys_sendmmsg+0xc4/0x210 [ 32.157657] ? __sys_connect+0xb7/0xe0 [ 32.157995] ? __audit_syscall_entry+0xce/0x140 [ 32.158388] ? syscall_trace_enter.isra.0+0x12c/0x1a0 [ 32.158820] __x64_sys_sendmmsg+0x24/0x30 [ 32.159171] do_syscall_64+0x38/0x90 [ 32.159493] entry_SYSCALL_64_after_hwframe+0x72/0xdc Fix that by reducing txq number as the non-existent primary-dev does.

Affected products

Linux kernel: 4.18 — fixed in 6.3

How to fix

Upgrade to a fixed version: Linux kernel 6.3. Check the vendor advisory for mitigations.

References

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