Linux Kernel up to 6.12.77/6.18.18/6.19.8 do_user_addr_fault denial of service

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.12.77/6.18.18/6.19.8. This issue affects the function do_user_addr_fault. Such manipulation leads to denial of service. This vulnerability is referenced as CVE-2026-43467. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.77/6.18.18/6.19.8 and classified as critical. Affected by this issue is the function do_user_addr_fault. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Fix crash when moving to switchdev mode When moving to switchdev mode when the device doesn't support IPsec, we try to clean up the IPsec resources anyway which causes the crash below, fix that by correctly checking for IPsec support before trying to clean up its resources. [27642.515799] WARNING: arch/x86/mm/fault.c:1276 at do_user_addr_fault+0x18a/0x680, CPU#4: devlink/6490 [27642.517159] Modules linked in: xt_conntrack xt_MASQUERADE ip6table_nat ip6table_filter ip6_tables iptable_nat nf_nat xt_addrtype rpcsec_gss_krb5 auth_rpcgss oid_registry overlay mlx5_fwctl nfnetlink zram zsmalloc mlx5_ib fuse rpcrdma rdma_ucm ib_uverbs ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm mlx5_core ib_core [27642.521358] CPU: 4 UID: 0 PID: 6490 Comm: devlink Not tainted 6.19.0-rc5_for_upstream_min_debug_2026_01_14_16_47 #1 NONE [27642.522923] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [27642.524528] RIP: 0010:do_user_addr_fault+0x18a/0x680 [27642.525362] Code: ff 0f 84 75 03 00 00 48 89 ee 4c 89 e7 e8 5e b9 22 00 49 89 c0 48 85 c0 0f 84 a8 02 00 00 f7 c3 60 80 00 00 74 22 31 c9 eb ae <0f> 0b 48 83 c4 10 48 89 ea 48 89 de 4c 89 f7 5b 5d 41 5c 41 5d 41 [27642.528166] RSP: 0018:ffff88810770f6b8 EFLAGS: 00010046 [27642.529038] RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffff88810b980f00 [27642.530158] RDX: 00000000000000a0 RSI: 0000000000000002 RDI: ffff88810770f728 [27642.531270] RBP: 00000000000000a0 R08: 0000000000000000 R09: 0000000000000000 [27642.532383] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888103f3c4c0 [27642.533499] R13: 0000000000000000 R14: ffff88810770f728 R15: 0000000000000000 [27642.534614] FS: 00007f197c741740(0000) GS:ffff88856a94c000(0000) knlGS:0000000000000000 [27642.535915] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27642.536858] CR2: 00000000000000a0 CR3: 000000011334c003 CR4: 0000000000172eb0 [27642.537982] Call Trace: [27642.538466] <TASK> [27642.538907] exc_page_fault+0x76/0x140 [27642.539583] asm_exc_page_fault+0x22/0x30 [27642.540282] RIP: 0010:_raw_spin_lock_irqsave+0x10/0x30 [27642.541134] Code: 07 85 c0 75 11 ba ff 00 00 00 f0 0f b1 17 75 06 b8 01 00 00 00 c3 31 c0 c3 90 0f 1f 44 00 00 53 9c 5b fa 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 05 48 89 d8 5b c3 89 c6 e8 7e 02 00 00 48 89 d8 5b [27642.543936] RSP: 0018:ffff88810770f7d8 EFLAGS: 00010046 [27642.544803] RAX: 0000000000000000 RBX: 0000000000000202 RCX: ffff888113ad96d8 [27642.545916] RDX: 0000000000000001 RSI: ffff88810770f818 RDI: 00000000000000a0 [27642.547027] RBP: 0000000000000098 R08: 0000000000000400 R09: ffff88810b980f00 [27642.548140] R10: 0000000000000001 R11: ffff888101845a80 R12: 00000000000000a8 [27642.549263] R13: ffffffffa02a9060 R14: 00000000000000a0 R15: ffff8881130d8a40 [27642.550379] complete_all+0x20/0x90 [27642.551010] mlx5e_ipsec_disable_events+0xb6/0xf0 [mlx5_core] [27642.552022] mlx5e_nic_disable+0x12d/0x220 [mlx5_core] [27642.552929] mlx5e_detach_netdev+0x66/0xf0 [mlx5_core] [27642.553822] mlx5e_netdev_change_profile+0x5b/0x120 [mlx5_core] [27642.554821] mlx5e_vport_rep_load+0x419/0x590 [mlx5_core] [27642.555757] ? xa_load+0x53/0x90 [27642.556361] __esw_offloads_load_rep+0x54/0x70 [mlx5_core] [27642.557328] mlx5_esw_offloads_rep_load+0x45/0xd0 [mlx5_core] [27642.558320] esw_offloads_enable+0xb4b/0xc90 [mlx5_core] [27642.559247] mlx5_eswitch_enable_locked+0x34e/0x4f0 [mlx5_core] [27642.560257] ? mlx5_rescan_drivers_locked+0x222/0x2d0 [mlx5_core] [27642.561284] mlx5_devlink_eswitch_mode_set+0x5ac/0x9c0 [mlx5_core] [27642.562334] ? devlink_rate_set_ops_supported+0x21/0x3a0 [27642.563220] devlink_nl_eswitch_set_doit+0x67/0xe0 [27642.564026] genl_family_rcv_msg_doit+0xe0/0x130 [27642.564816] genl_rcv_msg+0x183/0x290 [27642.565466] ? __devlink_nl_pre_doit.isra.0+0x160/0x160 [27642.566329] ? d ---truncated---

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-43467 since 05/01/2026. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 313466 (Linux Distros Unpatched Vulnerability : CVE-2026-43467), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.78, 6.18.19 or 6.19.9 eliminates this vulnerability. Applying the patch 05c9a6df3646cdd25e0e10e6ef2d20cdba3ed8f9/835778685f157b4fd4683b670cfe4010265bac60/bc72f739f398d9d2e4f3d06f3f75fe98876d5579/24b2795f9683e092dc22a68f487e7aaaf2ddafea 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 (313466). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.12.64
• 6.12.65
• 6.12.66
• 6.12.67
• 6.12.68
• 6.12.69
• 6.12.70
• 6.12.71
• 6.12.72
• 6.12.73
• 6.12.74
• 6.12.75
• 6.12.76
• 6.12.77
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5
• 6.19.6
• 6.19.7
• 6.19.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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Exploitinginfo

Threat Intelligenceinfo

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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