CVE-2025-21717: linux kernel vulnerability

What is known

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: add missing cpu_to_node to kvzalloc_node in mlx5e_open_xdpredirect_sq kvzalloc_node is not doing a runtime check on the node argument (__alloc_pages_node_noprof does have a VM_BUG_ON, but it expands to nothing on !CONFIG_DEBUG_VM builds), so doing any ethtool/netlink operation that calls mlx5e_open on a CPU that's larger that MAX_NUMNODES triggers OOB access and panic (see the trace below). Add missing cpu_to_node call to convert cpu id to node id. [ 165.427394] mlx5_core 0000:5c:00.0 beth1: Link up [ 166.479327] BUG: unable to handle page fault for address: 0000000800000010 [ 166.494592] #PF: supervisor read access in kernel mode [ 166.505995] #PF: error_code(0x0000) - not-present page ... [ 166.816958] Call Trace: [ 166.822380] <TASK> [ 166.827034] ? __die_body+0x64/0xb0 [ 166.834774] ? page_fault_oops+0x2cd/0x3f0 [ 166.843862] ? exc_page_fault+0x63/0x130 [ 166.852564] ? asm_exc_page_fault+0x22/0x30 [ 166.861843] ? __kvmalloc_node_noprof+0x43/0xd0 [ 166.871897] ? get_partial_node+0x1c/0x320 [ 166.880983] ? deactivate_slab+0x269/0x2b0 [ 166.890069] ___slab_alloc+0x521/0xa90 [ 166.898389] ? __kvmalloc_node_noprof+0x43/0xd0 [ 166.908442] __kmalloc_node_noprof+0x216/0x3f0 [ 166.918302] ? __kvmalloc_node_noprof+0x43/0xd0 [ 166.928354] __kvmalloc_node_noprof+0x43/0xd0 [ 166.938021] mlx5e_open_channels+0x5e2/0xc00 [ 166.947496] mlx5e_open_locked+0x3e/0xf0 [ 166.956201] mlx5e_open+0x23/0x50 [ 166.963551] __dev_open+0x114/0x1c0 [ 166.971292] __dev_change_flags+0xa2/0x1b0 [ 166.980378] dev_change_flags+0x21/0x60 [ 166.988887] do_setlink+0x38d/0xf20 [ 166.996628] ? ep_poll_callback+0x1b9/0x240 [ 167.005910] ? __nla_validate_parse.llvm.10713395753544950386+0x80/0xd70 [ 167.020782] ? __wake_up_sync_key+0x52/0x80 [ 167.030066] ? __mutex_lock+0xff/0x550 [ 167.038382] ? security_capable+0x50/0x90 [ 167.047279] rtnl_setlink+0x1c9/0x210 [ 167.055403] ? ep_poll_callback+0x1b9/0x240 [ 167.064684] ? security_capable+0x50/0x90 [ 167.073579] rtnetlink_rcv_msg+0x2f9/0x310 [ 167.082667] ? rtnetlink_bind+0x30/0x30 [ 167.091173] netlink_rcv_skb+0xb1/0xe0 [ 167.099492] netlink_unicast+0x20f/0x2e0 [ 167.108191] netlink_sendmsg+0x389/0x420 [ 167.116896] __sys_sendto+0x158/0x1c0 [ 167.125024] __x64_sys_sendto+0x22/0x30 [ 167.133534] do_syscall_64+0x63/0x130 [ 167.141657] ? __irq_exit_rcu.llvm.17843942359718260576+0x52/0xd0 [ 167.155181] entry_SYSCALL_64_after_hwframe+0x4b/0x53

Business impact

Successful exploitation of CVE-2025-21717, a high vulnerability (CVSS 7.8) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
• Reference
• Reference