{"id":"CVE-2026-43466","title":"net/mlx5e: Fix DMA FIFO desync on error CQE SQ recovery","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix DMA FIFO desync on error CQE SQ recovery\n\nIn case of a TX error CQE, a recovery flow is triggered,\nmlx5e_reset_txqsq_cc_pc() resets dma_fifo_cc to 0 but …","severity":"high","cvss":8.2,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 821f85d619f7f22cda7b9d7de89cf5eeb1d11544","Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 6eb68ecc5acc3b319986566c595990b8a7265b23","Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 6f41f7812bfa7f991b732a4b45c5c52fc4be3b4e","Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 383b37c04a4827ba60b2bafc1a6cdfd995aed58f","Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 9c5ee9b981ee050b73fdf3f4a2464d6f1a8e10a8","Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < ce1b19dd0684eeb68a124c11085bd611260b36d9","Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 829efcccfa8f69db5dc8332961295587d218cee6","Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 1633111d69053512d099658d4a05fc736fab36b0","Linux 4.17"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-16T15:17:38.531482Z"},"published":"2026-05-08","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:42.642Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43466","references":[{"url":"https://git.kernel.org/stable/c/821f85d619f7f22cda7b9d7de89cf5eeb1d11544"},{"url":"https://git.kernel.org/stable/c/6eb68ecc5acc3b319986566c595990b8a7265b23"},{"url":"https://git.kernel.org/stable/c/6f41f7812bfa7f991b732a4b45c5c52fc4be3b4e"},{"url":"https://git.kernel.org/stable/c/383b37c04a4827ba60b2bafc1a6cdfd995aed58f"},{"url":"https://git.kernel.org/stable/c/9c5ee9b981ee050b73fdf3f4a2464d6f1a8e10a8"},{"url":"https://git.kernel.org/stable/c/ce1b19dd0684eeb68a124c11085bd611260b36d9"},{"url":"https://git.kernel.org/stable/c/829efcccfa8f69db5dc8332961295587d218cee6"},{"url":"https://git.kernel.org/stable/c/1633111d69053512d099658d4a05fc736fab36b0"}],"tags":["cve.org"],"epss":0.00606,"epssPercentile":0.47898,"ingestedAt":"2026-10-16T17:24:46.697Z","slug":"CVE-2026-43466","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix DMA FIFO desync on error CQE SQ recovery\n\nIn case of a TX error CQE, a recovery flow is triggered,\nmlx5e_reset_txqsq_cc_pc() resets dma_fifo_cc to 0 but not dma_fifo_pc,\ndesyncing the DMA FIFO producer and consumer.\n\nAfter recovery, the producer pushes new DMA entries at the old\ndma_fifo_pc, while the consumer reads from position 0.\nThis causes us to unmap stale DMA addresses from before the recovery.\n\nThe DMA FIFO is a purely software construct with no HW counterpart.\nAt the point of reset, all WQEs have been flushed so dma_fifo_cc is\nalready equal to dma_fifo_pc. There is no need to reset either counter,\nsimilar to how skb_fifo pc/cc are untouched.\n\nRemove the 'dma_fifo_cc = 0' reset.\n\nThis fixes the following WARNING:\n    WARNING: CPU: 0 PID: 0 at drivers/iommu/dma-iommu.c:1240 iommu_dma_unmap_page+0x79/0x90\n    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]\n    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\n    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014\n    RIP: 0010:iommu_dma_unmap_page+0x79/0x90\n    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\n    Call Trace:\n     <IRQ>\n     ? __warn+0x7d/0x110\n     ? iommu_dma_unmap_page+0x79/0x90\n     ? report_bug+0x16d/0x180\n     ? handle_bug+0x4f/0x90\n     ? exc_invalid_op+0x14/0x70\n     ? asm_exc_invalid_op+0x16/0x20\n     ? iommu_dma_unmap_page+0x79/0x90\n     ? iommu_dma_unmap_page+0x2e/0x90\n     dma_unmap_page_attrs+0x10d/0x1b0\n     mlx5e_tx_wi_dma_unmap+0xbe/0x120 [mlx5_core]\n     mlx5e_poll_tx_cq+0x16d/0x690 [mlx5_core]\n     mlx5e_napi_poll+0x8b/0xac0 [mlx5_core]\n     __napi_poll+0x24/0x190\n     net_rx_action+0x32a/0x3b0\n     ? mlx5_eq_comp_int+0x7e/0x270 [mlx5_core]\n     ? notifier_call_chain+0x35/0xa0\n     handle_softirqs+0xc9/0x270\n     irq_exit_rcu+0x71/0xd0\n     common_interrupt+0x7f/0xa0\n     </IRQ>\n     <TASK>\n     asm_common_interrupt+0x22/0x40\n\n## Affected\n\n- `Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 821f85d619f7f22cda7b9d7de89cf5eeb1d11544`\n- `Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 6eb68ecc5acc3b319986566c595990b8a7265b23`\n- `Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 6f41f7812bfa7f991b732a4b45c5c52fc4be3b4e`\n- `Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 383b37c04a4827ba60b2bafc1a6cdfd995aed58f`\n- `Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 9c5ee9b981ee050b73fdf3f4a2464d6f1a8e10a8`\n- `Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < ce1b19dd0684eeb68a124c11085bd611260b36d9`\n- `Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 829efcccfa8f69db5dc8332961295587d218cee6`\n- `Linux >= db75373c91b0cfb6a68ad6ae88721e4e21ae6261 < 1633111d69053512d099658d4a05fc736fab36b0`\n- `Linux 4.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":45.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}