CVE-2025-21717 net/mlx5e: add missing cpu_to_node to kvzalloc_node in mlx5e_open_xdpredirect_sq

High 7.8 Published 27 Feb 2025 Updated 5 Aug 2026

A missing CPU-to-node conversion in the mlx5e driver causes an out-of-bounds access and kernel panic when opening network interfaces on high-CPU systems.

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-2025-21717?

CVE-2025-21717 is a high-severity memory corruption vulnerability in Linux kernel, published on 27 Feb 2025. 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:

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

Weakness: CWE-125

Which versions are affected by CVE-2025-21717?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-21717?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-21717 being exploited?

There is no known exploitation of CVE-2025-21717 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2025-21717, GHSA-6v7v-ggwx-mwx7, UBUNTU-CVE-2025-21717.