CVE-2026-23046 in Linux
Summary
by MITRE • 02/04/2026
In the Linux kernel, the following vulnerability has been resolved:
virtio_net: fix device mismatch in devm_kzalloc/devm_kfree
Initial rss_hdr allocation uses virtio_device->device, but virtnet_set_queues() frees using net_device->device. This device mismatch causing below devres warning
[ 3788.514041] ------------[ cut here ]------------
[ 3788.514044] WARNING: drivers/base/devres.c:1095 at devm_kfree+0x84/0x98, CPU#16: vdpa/1463
[ 3788.514054] Modules linked in: octep_vdpa virtio_net virtio_vdpa [last unloaded: virtio_vdpa]
[ 3788.514064] CPU: 16 UID: 0 PID: 1463 Comm: vdpa Tainted: G W 6.18.0 #10 PREEMPT
[ 3788.514067] Tainted: [W]=WARN
[ 3788.514069] Hardware name: Marvell CN106XX board (DT)
[ 3788.514071] pstate: 63400009 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
[ 3788.514074] pc : devm_kfree+0x84/0x98
[ 3788.514076] lr : devm_kfree+0x54/0x98
[ 3788.514079] sp : ffff800084e2f220
[ 3788.514080] x29: ffff800084e2f220 x28: ffff0003b2366000 x27: 000000000000003f
[ 3788.514085] x26: 000000000000003f x25: ffff000106f17c10 x24: 0000000000000080
[ 3788.514089] x23: ffff00045bb8ab08 x22: ffff00045bb8a000 x21: 0000000000000018
[ 3788.514093] x20: ffff0004355c3080 x19: ffff00045bb8aa00 x18: 0000000000080000
[ 3788.514098] x17: 0000000000000040 x16: 000000000000001f x15: 000000000007ffff
[ 3788.514102] x14: 0000000000000488 x13: 0000000000000005 x12: 00000000000fffff
[ 3788.514106] x11: ffffffffffffffff x10: 0000000000000005 x9 : ffff800080c8c05c
[ 3788.514110] x8 : ffff800084e2eeb8 x7 : 0000000000000000 x6 : 000000000000003f
[ 3788.514115] x5 : ffff8000831bafe0 x4 : ffff800080c8b010 x3 : ffff0004355c3080
[ 3788.514119] x2 : ffff0004355c3080 x1 : 0000000000000000 x0 : 0000000000000000
[ 3788.514123] Call trace:
[ 3788.514125] devm_kfree+0x84/0x98 (P)
[ 3788.514129] virtnet_set_queues+0x134/0x2e8 [virtio_net]
[ 3788.514135] virtnet_probe+0x9c0/0xe00 [virtio_net]
[ 3788.514139] virtio_dev_probe+0x1e0/0x338
[ 3788.514144] really_probe+0xc8/0x3a0
[ 3788.514149] __driver_probe_device+0x84/0x170
[ 3788.514152] driver_probe_device+0x44/0x120
[ 3788.514155] __device_attach_driver+0xc4/0x168
[ 3788.514158] bus_for_each_drv+0x8c/0xf0
[ 3788.514161] __device_attach+0xa4/0x1c0
[ 3788.514164] device_initial_probe+0x1c/0x30
[ 3788.514168] bus_probe_device+0xb4/0xc0
[ 3788.514170] device_add+0x614/0x828
[ 3788.514173] register_virtio_device+0x214/0x258
[ 3788.514175] virtio_vdpa_probe+0xa0/0x110 [virtio_vdpa]
[ 3788.514179] vdpa_dev_probe+0xa8/0xd8
[ 3788.514183] really_probe+0xc8/0x3a0
[ 3788.514186] __driver_probe_device+0x84/0x170
[ 3788.514189] driver_probe_device+0x44/0x120
[ 3788.514192] __device_attach_driver+0xc4/0x168
[ 3788.514195] bus_for_each_drv+0x8c/0xf0
[ 3788.514197] __device_attach+0xa4/0x1c0
[ 3788.514200] device_initial_probe+0x1c/0x30
[ 3788.514203] bus_probe_device+0xb4/0xc0
[ 3788.514206] device_add+0x614/0x828
[ 3788.514209] _vdpa_register_device+0x58/0x88
[ 3788.514211] octep_vdpa_dev_add+0x104/0x228 [octep_vdpa]
[ 3788.514215] vdpa_nl_cmd_dev_add_set_doit+0x2d0/0x3c0
[ 3788.514218] genl_family_rcv_msg_doit+0xe4/0x158
[ 3788.514222] genl_rcv_msg+0x218/0x298
[ 3788.514225] netlink_rcv_skb+0x64/0x138
[ 3788.514229] genl_rcv+0x40/0x60
[ 3788.514233] netlink_unicast+0x32c/0x3b0
[ 3788.514237] netlink_sendmsg+0x170/0x3b8
[ 3788.514241] __sys_sendto+0x12c/0x1c0
[ 3788.514246] __arm64_sys_sendto+0x30/0x48
[ 3788.514249] invoke_syscall.constprop.0+0x58/0xf8
[ 3788.514255] do_el0_svc+0x48/0xd0
[ 3788.514259] el0_svc+0x48/0x210
[ 3788.514264] el0t_64_sync_handler+0xa0/0xe8
[ 3788.514268] el0t_64_sync+0x198/0x1a0
[ 3788.514271] ---[ end trace 0000000000000000 ]---
Fix by using virtio_device->device consistently for allocation and deallocation
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Analysis
by VulDB Data Team • 04/30/2026
The vulnerability described in CVE-2026-23046 resides within the Linux kernel's virtio_net driver, specifically manifesting as a device mismatch during memory management operations involving the devm_kzalloc and devm_kfree functions. This issue occurs during the initialization and configuration of virtual network devices, particularly when handling RSS (Receive Side Scaling) header allocations. The root cause stems from inconsistent use of device references during resource allocation and deallocation phases. The initial RSS header allocation utilizes the virtio_device->device context, while the subsequent freeing operation in virtnet_set_queues() employs net_device->device instead. This discrepancy creates a mismatch in the device context used for memory management, leading to improper resource tracking within the kernel's device resource management subsystem.
The technical flaw manifests as a warning message generated by the kernel's device resource management code located in drivers/base/devres.c at line 1095. This warning originates from the devm_kfree function when it attempts to free memory that was allocated with a different device context than the one currently associated with the freeing operation. The call trace demonstrates a complex sequence of function calls beginning with the virtio_vdpa probe mechanism and ultimately reaching the devm_kfree function, indicating that the issue impacts virtualized network environments using VDPA (Virtual Device API) interfaces. The warning appears during runtime when the kernel attempts to clean up resources associated with a virtual network device, specifically during the device initialization and queue configuration phases.
The operational impact of this vulnerability extends beyond mere warning messages, as it represents a potential resource management inconsistency that could lead to memory leaks, improper cleanup of virtual network device resources, or more severe system stability issues in virtualized environments. The vulnerability affects systems utilizing virtio_net drivers in conjunction with VDPA devices such as those found in Marvell CN106XX platforms, where virtualized network functionality is heavily relied upon. The improper device context handling during memory management operations could potentially result in resource corruption or failure to properly release allocated memory, which may accumulate over time and impact system performance or cause unexpected device behavior.
The fix for this vulnerability involves ensuring consistent usage of the virtio_device->device reference throughout both allocation and deallocation phases of the RSS header management. This approach aligns with established kernel development practices for device resource management and resolves the fundamental mismatch that causes the devres warning. The solution follows the principle of maintaining consistent device context references during memory management operations, which is consistent with common vulnerability patterns identified in CWE-765, where improper resource management leads to device context mismatches. This fix also aligns with ATT&CK techniques related to system resource manipulation and kernel-level privilege escalation through improper resource handling, though the immediate impact is more focused on resource management consistency than direct exploitation. The resolution ensures that all memory management operations within the virtio_net driver maintain proper device context alignment, preventing potential memory corruption or resource leak scenarios that could affect virtualized network performance and system stability.