CVE-2026-22993

MEDIUM

Linux kernel - Use After Free

Title source: llm

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>

Scores

CVSS v3 5.5
EPSS 0.0002
EPSS Percentile 3.7%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Classification

CWE
CWE-476
Status published

Affected Products (6)

linux/Kernel < 6.18.6linux
linux/linux_kernel < 6.18.6
linux/linux_kernel
linux/linux_kernel
linux/linux_kernel
linux/linux_kernel

Timeline

Published Jan 23, 2026
Tracked Since Feb 18, 2026