CVE-2026-23212 bonding: annotate data-races around slave->last_rx
A data race in the Linux kernel bonding driver can lead to inconsistent state, potentially causing instability or unexpected behavior.
- 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-2026-23212?
CVE-2026-23212 is a medium-severity vulnerability in Linux kernel, published on 18 Feb 2026. 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:
bonding: annotate data-races around slave->last_rx
slave->last_rx and slave->target_last_arp_rx[...] can be read and written locklessly. Add READ_ONCE() and WRITE_ONCE() annotations.
syzbot reported:
BUG: KCSAN: data-race in bond_rcv_validate / bond_rcv_validate
write to 0xffff888149f0d428 of 8 bytes by interrupt on cpu 1: bond_rcv_validate+0x202/0x7a0 drivers/net/bonding/bond_main.c:3335 bond_handle_frame+0xde/0x5e0 drivers/net/bonding/bond_main.c:1533 __netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6039 __netif_receive_skb_one_core net/core/dev.c:6150 [inline] __netif_receive_skb+0x59/0x270 net/core/dev.c:6265 netif_receive_skb_internal net/core/dev.c:6351 [inline] netif_receive_skb+0x4b/0x2d0 net/core/dev.c:6410 ...
write to 0xffff888149f0d428 of 8 bytes by interrupt on cpu 0: bond_rcv_validate+0x202/0x7a0 drivers/net/bonding/bond_main.c:3335 bond_handle_frame+0xde/0x5e0 drivers/net/bonding/bond_main.c:1533 __netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6039 __netif_receive_skb_one_core net/core/dev.c:6150 [inline] __netif_receive_skb+0x59/0x270 net/core/dev.c:6265 netif_receive_skb_internal net/core/dev.c:6351 [inline] netif_receive_skb+0x4b/0x2d0 net/core/dev.c:6410 br_netif_receive_skb net/bridge/br_input.c:30 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] ...
value changed: 0x0000000100005365 -> 0x0000000100005366
Which versions are affected by CVE-2026-23212?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23212?
Apply the vendor's patch.
Is CVE-2026-23212 being exploited?
There is no known exploitation of CVE-2026-23212 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-77865, BELL-CVE-2026-23212, DEBIAN-CVE-2026-23212, GHSA-phqg-p332-q7vc, ROOT-OS-DEBIAN-11-CVE-2026-23212, ROOT-OS-UBUNTU-2204-CVE-2026-23212 and 2 more.