CVE-2026-22993 idpf: Fix RSS LUT NULL ptr issue after soft reset

Medium 5.5 Published 23 Jan 2026 Updated 11 May 2026

A local attacker can cause a kernel crash by triggering a NULL pointer dereference in the idpf driver during a soft reset sequence.

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-2026-22993?

CVE-2026-22993 is a medium-severity vulnerability in Linux kernel, published on 23 Jan 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:

idpf: Fix RSS LUT NULL ptr issue after soft reset

During soft reset, the RSS LUT is freed and not restored unless the interface is up. If an ethtool command that accesses the rss lut is attempted immediately after reset, it will result in NULL ptr dereference. Also, there is no need to reset the rss lut if the soft reset does not involve queue count change.

After soft reset, set the RSS LUT to default values based on the updated queue count only if the reset was a result of a queue count change and the LUT was not configured by the user. In all other cases, don't touch the LUT.

Steps to reproduce:

** Bring the interface down (if up) ifconfig eth1 down

** update the queue count (eg., 27->20) ethtool -L eth1 combined 20

** display the RSS LUT ethtool -x eth1

[82375.558338] BUG: kernel NULL pointer dereference, address: 0000000000000000 [82375.558373] #PF: supervisor read access in kernel mode [82375.558391] #PF: error_code(0x0000) - not-present page [82375.558408] PGD 0 P4D 0 [82375.558421] Oops: Oops: 0000 [#1] SMP NOPTI <snip> [82375.558516] RIP: 0010:idpf_get_rxfh+0x108/0x150 [idpf] [82375.558786] Call Trace: [82375.558793] <TASK> [82375.558804] rss_prepare.isra.0+0x187/0x2a0 [82375.558827] rss_prepare_data+0x3a/0x50 [82375.558845] ethnl_default_doit+0x13d/0x3e0 [82375.558863] genl_family_rcv_msg_doit+0x11f/0x180 [82375.558886] genl_rcv_msg+0x1ad/0x2b0 [82375.558902] ? __pfx_ethnl_default_doit+0x10/0x10 [82375.558920] ? __pfx_genl_rcv_msg+0x10/0x10 [82375.558937] netlink_rcv_skb+0x58/0x100 [82375.558957] genl_rcv+0x2c/0x50 [82375.558971] netlink_unicast+0x289/0x3e0 [82375.558988] netlink_sendmsg+0x215/0x440 [82375.559005] __sys_sendto+0x234/0x240 [82375.559555] __x64_sys_sendto+0x28/0x30 [82375.560068] x64_sys_call+0x1909/0x1da0 [82375.560576] do_syscall_64+0x7a/0xfa0 [82375.561076] ? clear_bhb_loop+0x60/0xb0 [82375.561567] entry_SYSCALL_64_after_hwframe+0x76/0x7e <snip>

Weakness: CWE-476

Which versions are affected by CVE-2026-22993?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-22993?

Apply the vendor's patch.

Is CVE-2026-22993 being exploited?

There is no known exploitation of CVE-2026-22993 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2026-22993, DEBIAN-CVE-2026-22993, GHSA-42mq-7943-cj3h, ROOT-OS-DEBIAN-13-CVE-2026-22993, ROOT-OS-UBUNTU-2404-CVE-2026-22993, UBUNTU-CVE-2026-22993.