CVE-2025-38402 idpf: return 0 size for RSS key if not supported

Medium 5.5 Published Updated

A local attacker can cause a kernel crash by triggering an invalid memory allocation in the idpf driver when RSS is unsupported.

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-2025-38402?

CVE-2025-38402 is a medium-severity vulnerability in Linux kernel, published on 25 Jul 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:

idpf: return 0 size for RSS key if not supported

Returning -EOPNOTSUPP from function returning u32 is leading to cast and invalid size value as a result.

-EOPNOTSUPP as a size probably will lead to allocation fail.

Command: ethtool -x eth0 It is visible on all devices that don't have RSS caps set.

[ 136.615917] Call Trace: [ 136.615921] <TASK> [ 136.615927] ? __warn+0x89/0x130 [ 136.615942] ? __alloc_frozen_pages_noprof+0x322/0x330 [ 136.615953] ? report_bug+0x164/0x190 [ 136.615968] ? handle_bug+0x58/0x90 [ 136.615979] ? exc_invalid_op+0x17/0x70 [ 136.615987] ? asm_exc_invalid_op+0x1a/0x20 [ 136.616001] ? rss_prepare_get.constprop.0+0xb9/0x170 [ 136.616016] ? __alloc_frozen_pages_noprof+0x322/0x330 [ 136.616028] __alloc_pages_noprof+0xe/0x20 [ 136.616038] ___kmalloc_large_node+0x80/0x110 [ 136.616072] __kmalloc_large_node_noprof+0x1d/0xa0 [ 136.616081] __kmalloc_noprof+0x32c/0x4c0 [ 136.616098] ? rss_prepare_get.constprop.0+0xb9/0x170 [ 136.616105] rss_prepare_get.constprop.0+0xb9/0x170 [ 136.616114] ethnl_default_doit+0x107/0x3d0 [ 136.616131] genl_family_rcv_msg_doit+0x100/0x160 [ 136.616147] genl_rcv_msg+0x1b8/0x2c0 [ 136.616156] ? __pfx_ethnl_default_doit+0x10/0x10 [ 136.616168] ? __pfx_genl_rcv_msg+0x10/0x10 [ 136.616176] netlink_rcv_skb+0x58/0x110 [ 136.616186] genl_rcv+0x28/0x40 [ 136.616195] netlink_unicast+0x19b/0x290 [ 136.616206] netlink_sendmsg+0x222/0x490 [ 136.616215] __sys_sendto+0x1fd/0x210 [ 136.616233] __x64_sys_sendto+0x24/0x30 [ 136.616242] do_syscall_64+0x82/0x160 [ 136.616252] ? __sys_recvmsg+0x83/0xe0 [ 136.616265] ? syscall_exit_to_user_mode+0x10/0x210 [ 136.616275] ? do_syscall_64+0x8e/0x160 [ 136.616282] ? __count_memcg_events+0xa1/0x130 [ 136.616295] ? count_memcg_events.constprop.0+0x1a/0x30 [ 136.616306] ? handle_mm_fault+0xae/0x2d0 [ 136.616319] ? do_user_addr_fault+0x379/0x670 [ 136.616328] ? clear_bhb_loop+0x45/0xa0 [ 136.616340] ? clear_bhb_loop+0x45/0xa0 [ 136.616349] ? clear_bhb_loop+0x45/0xa0 [ 136.616359] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 136.616369] RIP: 0033:0x7fd30ba7b047 [ 136.616376] Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d bd d5 0c 00 00 41 89 ca 74 10 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 71 c3 55 48 83 ec 30 44 89 4c 24 2c 4c 89 44 [ 136.616381] RSP: 002b:00007ffde1796d68 EFLAGS: 00000202 ORIG_RAX: 000000000000002c [ 136.616388] RAX: ffffffffffffffda RBX: 000055d7bd89f2a0 RCX: 00007fd30ba7b047 [ 136.616392] RDX: 0000000000000028 RSI: 000055d7bd89f3b0 RDI: 0000000000000003 [ 136.616396] RBP: 00007ffde1796e10 R08: 00007fd30bb4e200 R09: 000000000000000c [ 136.616399] R10: 0000000000000000 R11: 0000000000000202 R12: 000055d7bd89f340 [ 136.616403] R13: 000055d7bd89f3b0 R14: 000055d78943f200 R15: 0000000000000000

Weakness: CWE-476

Which versions are affected by CVE-2025-38402?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-38402?

Apply the vendor's patch.

Is CVE-2025-38402 being exploited?

There is no known exploitation of CVE-2025-38402 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2025-38402, DEBIAN-CVE-2025-38402, GHSA-xq77-3x66-fcxc, ROOT-OS-UBUNTU-2404-CVE-2025-38402, UBUNTU-CVE-2025-38402.

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