Linux Kernel up to 6.19.8 mlx5e mlx5e_reset_txqsq_cc_pc privilege escalation

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6.7$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.19.8. It has been rated as problematic. Affected is the function mlx5e_reset_txqsq_cc_pc of the component mlx5e. Performing a manipulation results in an unknown weakness. This vulnerability is cataloged as CVE-2026-43466. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.19.8. It has been classified as problematic. This affects the function mlx5e_reset_txqsq_cc_pc of the component mlx5e. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix DMA FIFO desync on error CQE SQ recovery In case of a TX error CQE, a recovery flow is triggered, mlx5e_reset_txqsq_cc_pc() resets dma_fifo_cc to 0 but not dma_fifo_pc, desyncing the DMA FIFO producer and consumer. After recovery, the producer pushes new DMA entries at the old dma_fifo_pc, while the consumer reads from position 0. This causes us to unmap stale DMA addresses from before the recovery. The DMA FIFO is a purely software construct with no HW counterpart. At the point of reset, all WQEs have been flushed so dma_fifo_cc is already equal to dma_fifo_pc. There is no need to reset either counter, similar to how skb_fifo pc/cc are untouched. Remove the 'dma_fifo_cc = 0' reset. This fixes the following WARNING: WARNING: CPU: 0 PID: 0 at drivers/iommu/dma-iommu.c:1240 iommu_dma_unmap_page+0x79/0x90 Modules linked in: mlx5_vdpa vringh vdpa bonding mlx5_ib mlx5_vfio_pci ipip mlx5_fwctl tunnel4 mlx5_core ib_ipoib geneve ip6_gre ip_gre gre nf_tables ip6_tunnel rdma_ucm ib_uverbs ib_umad vfio_pci vfio_pci_core act_mirred act_skbedit act_vlan vhost_net vhost tap ip6table_mangle ip6table_nat ip6table_filter ip6_tables iptable_mangle cls_matchall nfnetlink_cttimeout act_gact cls_flower sch_ingress vhost_iotlb iptable_raw tunnel6 vfio_iommu_type1 vfio openvswitch nsh rpcsec_gss_krb5 auth_rpcgss oid_registry xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat nf_nat xt_addrtype br_netfilter overlay zram zsmalloc rpcrdma ib_iser libiscsi scsi_transport_iscsi rdma_cm iw_cm ib_cm ib_core fuse [last unloaded: nf_tables] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.13.0-rc5_for_upstream_min_debug_2024_12_30_21_33 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:iommu_dma_unmap_page+0x79/0x90 Code: 2b 4d 3b 21 72 26 4d 3b 61 08 73 20 49 89 d8 44 89 f9 5b 4c 89 f2 4c 89 e6 48 89 ef 5d 41 5c 41 5d 41 5e 41 5f e9 c7 ae 9e ff <0f> 0b 5b 5d 41 5c 41 5d 41 5e 41 5f c3 66 2e 0f 1f 84 00 00 00 00 Call Trace: <IRQ> ? __warn+0x7d/0x110 ? iommu_dma_unmap_page+0x79/0x90 ? report_bug+0x16d/0x180 ? handle_bug+0x4f/0x90 ? exc_invalid_op+0x14/0x70 ? asm_exc_invalid_op+0x16/0x20 ? iommu_dma_unmap_page+0x79/0x90 ? iommu_dma_unmap_page+0x2e/0x90 dma_unmap_page_attrs+0x10d/0x1b0 mlx5e_tx_wi_dma_unmap+0xbe/0x120 [mlx5_core] mlx5e_poll_tx_cq+0x16d/0x690 [mlx5_core] mlx5e_napi_poll+0x8b/0xac0 [mlx5_core] __napi_poll+0x24/0x190 net_rx_action+0x32a/0x3b0 ? mlx5_eq_comp_int+0x7e/0x270 [mlx5_core] ? notifier_call_chain+0x35/0xa0 handle_softirqs+0xc9/0x270 irq_exit_rcu+0x71/0xd0 common_interrupt+0x7f/0xa0 </IRQ> <TASK> asm_common_interrupt+0x22/0x40

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-43466 since 05/01/2026. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/25/2026).

The vulnerability scanner Nessus provides a plugin with the ID 329305 (openSUSE 16: cluster-md-kmp-64kb / cluster-md-kmp-azure / cluster-md-kmp-default / etc (openSUSE-SU-2026:21388-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.19 or 6.19.9 eliminates this vulnerability. Applying the patch 821f85d619f7f22cda7b9d7de89cf5eeb1d11544/6eb68ecc5acc3b319986566c595990b8a7265b23/6f41f7812bfa7f991b732a4b45c5c52fc4be3b4e/383b37c04a4827ba60b2bafc1a6cdfd995aed58f/9c5ee9b981ee050b73fdf3f4a2464d6f1a8e10a8/ce1b19dd0684eeb68a124c11085bd611260b36d9/829efcccfa8f69db5dc8332961295587d218cee6/1633111d69053512d099658d4a05fc736fab36b0 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (329305). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.8
VulDB Meta Temp Score: 6.7

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.2
CNA Vector (Linux): 🔒

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 329305
Nessus Name: openSUSE 16: cluster-md-kmp-64kb / cluster-md-kmp-azure / cluster-md-kmp-default / etc (openSUSE-SU-2026:21388-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.253/5.15.203/6.1.167/6.6.130/6.12.78/6.18.19/6.19.9
Patch: 821f85d619f7f22cda7b9d7de89cf5eeb1d11544/6eb68ecc5acc3b319986566c595990b8a7265b23/6f41f7812bfa7f991b732a4b45c5c52fc4be3b4e/383b37c04a4827ba60b2bafc1a6cdfd995aed58f/9c5ee9b981ee050b73fdf3f4a2464d6f1a8e10a8/ce1b19dd0684eeb68a124c11085bd611260b36d9/829efcccfa8f69db5dc8332961295587d218cee6/1633111d69053512d099658d4a05fc736fab36b0

Timelineinfo

05/01/2026 CVE reserved
05/08/2026 +7 days Advisory disclosed
05/08/2026 +0 days VulDB entry created
07/25/2026 +78 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-43466 (🔒)
GCVE (CVE): GCVE-0-2026-43466
GCVE (VulDB): GCVE-100-362229

Entryinfo

Created: 05/08/2026 18:29
Updated: 07/25/2026 12:27
Changes: 05/08/2026 18:29 (57), 05/22/2026 08:14 (12), 07/25/2026 12:27 (4)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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