Bug 2432663 (CVE-2026-22996)

Summary:	CVE-2026-22996 kernel: net/mlx5e: Don't store mlx5e_priv in mlx5e_dev devlink priv
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Security
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A NULL pointer dereference vulnerability was found in the Mellanox mlx5 Ethernet driver in the Linux kernel. The driver stores a pointer to mlx5e_priv in the devlink private data, but this structure can be zeroed out (memset to 0) when profile attachment fails. Subsequent access to the zeroed structure during device removal causes a NULL pointer dereference and kernel crash.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-01-25 15:01:55 UTC

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: Don't store mlx5e_priv in mlx5e_dev devlink priv

mlx5e_priv is an unstable structure that can be memset(0) if profile
attaching fails, mlx5e_priv in mlx5e_dev devlink private is used to
reference the netdev and mdev associated with that struct. Instead,
store netdev directly into mlx5e_dev and get mdev from the containing
mlx5_adev aux device structure.

This fixes a kernel oops in mlx5e_remove when switchdev mode fails due
to change profile failure.

$ devlink dev eswitch set pci/0000:00:03.0 mode switchdev
Error: mlx5_core: Failed setting eswitch to offloads.
dmesg:
workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12
mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: new profile init failed, -12
workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12
mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: failed to rollback to orig profile, -12

$ devlink dev reload pci/0000:00:03.0 ==> oops

BUG: kernel NULL pointer dereference, address: 0000000000000520
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 3 UID: 0 PID: 521 Comm: devlink Not tainted 6.18.0-rc5+ #117 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:mlx5e_remove+0x68/0x130
RSP: 0018:ffffc900034838f0 EFLAGS: 00010246
RAX: ffff88810283c380 RBX: ffff888101874400 RCX: ffffffff826ffc45
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff888102d789c0 R08: ffff8881007137f0 R09: ffff888100264e10
R10: ffffc90003483898 R11: ffffc900034838a0 R12: ffff888100d261a0
R13: ffff888100d261a0 R14: ffff8881018749a0 R15: ffff888101874400
FS:  00007f8565fea740(0000) GS:ffff88856a759000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000520 CR3: 000000010b11a004 CR4: 0000000000370ef0
Call Trace:
 <TASK>
 device_release_driver_internal+0x19c/0x200
 bus_remove_device+0xc6/0x130
 device_del+0x160/0x3d0
 ? devl_param_driverinit_value_get+0x2d/0x90
 mlx5_detach_device+0x89/0xe0
 mlx5_unload_one_devl_locked+0x3a/0x70
 mlx5_devlink_reload_down+0xc8/0x220
 devlink_reload+0x7d/0x260
 devlink_nl_reload_doit+0x45b/0x5a0
 genl_family_rcv_msg_doit+0xe8/0x140

Comment 1 Alexander B 2026-01-26 08:47:06 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026012532-CVE-2026-22996-f977@gregkh/T