CVE-2025-21717: linux kernel Out-of-bounds Read — Fix

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

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CVSS v3.1 Score

7.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor	Product	Versions
linux	linux_kernel	6.13 — 6.13.2

References

Advisories & Patches

https://git.kernel.org/stable/c/979284535aaf12a287a2f43d9d5dfcbdc1dc4cac https://git.kernel.org/stable/c/a275db45b4161d01716559dd7557db9ea0450952

Frequently Asked Questions

What is CVE-2025-21717? +

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 It has a CVSS v3.1 base score of 7.1 (HIGH).

How severe is CVE-2025-21717? +

CVE-2025-21717 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-21717? +

CVE-2025-21717 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-21717? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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