Unity Linux 20.1020e / 20.1050e / 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-142481)

high Nessus Plugin ID 370763

Synopsis

The Unity Linux host is missing one or more security updates.

Description

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-142481 advisory.

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

RDMA/rxe: Fix a use-after-free problem in rxe_mmap

rxe_mmap() removes a rxe_mmap_info struct from the pending_mmaps list and releases pending_lock while the struct's kref is still at 1:

list_del_init(&ip->pending_mmaps);
spin_unlock_bh(&rxe->pending_lock); /* ref == 1, no lock held */ ret = remap_vmalloc_range(vma, ip->obj, 0); /* walks PTEs */ [...] rxe_vma_open(vma); /* kref_get, ref 2 */ remap_vmalloc_range_partial() walks PTEs without any lock.

A concurrent DESTROY_CQ ioctl on another CPU calls:

kref_put(&q->ip->ref, rxe_mmap_release) /* ref 10 */ vfree(ip->obj) /* clears vmalloc PTEs mid-walk */ kfree(ip) /* frees rxe_mmap_info */

This yields:

1. Kernel crash, vmalloc_to_page() returns NULL when vfree wins the per-PTE race -> vm_insert_page(NULL) GPF in validate_page_before_insert

2. Page UAF, vmalloc_to_page() reads a stale PTE before vfree clears it. User VMA holds a PTE to a free'd page which might eventually get reallocated later by vmalloc which allows the attacker to get a clean page-level UAF.

It is worth noting that even though a page-level UAF is possible given the strong primitive, it is statistically very difficult to achieve given the very short time window (after the last insert_page and before the kref_get).

The call trace are as below:

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 1000 PID: 413 Comm: poc Not tainted 7.0.0-rc5-dirty #28 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:validate_page_before_insert+0x32/0x300 Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 e8 93 b5 a3 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 7b 02 00 00 4c 8b 63 08 31 ff 4d 89 e5 41 83 e5 RSP: 0018:ffff88811b15f2f0 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008 RBP: ffff88811b15f318 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881181eee00 R13: 0000000000000000 R14: ffff8881181eee00 R15: ffff8881181eee20 FS: 00007b1e000f76c0(0000) GS:ffff8884268e0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007b1e00a24ac0 CR3: 0000000116eb3000 CR4: 00000000000006f0 Call Trace:
<TASK> insert_page+0x8f/0x190 ? __pfx_insert_page+0x10/0x10 ? kasan_save_alloc_info+0x38/0x60 vm_insert_page+0x2e7/0x400 remap_vmalloc_range_partial+0x212/0x3e0 remap_vmalloc_range+0x6e/0xb0 ? __kasan_check_write+0x14/0x30 rxe_mmap+0x2e9/0x5d0 ib_uverbs_mmap+0x1ad/0x2c0
__mmap_region+0x12c2/0x2ad0 ? __pfx___mmap_region+0x10/0x10 ? __sanitizer_cov_trace_switch+0x58/0xb0 ? mas_prev_slot+0x360/0x39c0 ? __sanitizer_cov_trace_switch+0x58/0xb0 ? mas_next_slot+0x1e5b/0x2f40 ? __sanitizer_cov_trace_cmp8+0x18/0x30 ? unmapped_area_topdown+0x4dd/0x610 ? kfree+0x1b1/0x440 ? free_cpumask_var+0x16/0x30 ? __kasan_slab_free+0x7d/0xa0 ? __sanitizer_cov_trace_cmp8+0x18/0x30 mmap_region+0x2e6/0x3c0 do_mmap+0xa3e/0x12a0 ? __pfx_do_mmap+0x10/0x10 ? __kasan_check_write+0x14/0x30 ? down_write_killable+0xba/0x160 ? __pfx_down_write_killable+0x10/0x10 ? __sanitizer_cov_trace_cmp4+0x16/0x30 vm_mmap_pgoff+0x2d4/0x4a0 ? __pfx_vm_mmap_pgoff+0x10/0x10 ? fget+0x1bf/0x270 ksys_mmap_pgoff+0x40c/0x690 ? __sanitizer_cov_trace_const_cmp4+0x16/0x30 ? __pfx_ksys_mmap_pgoff+0x10/0x10 ? __kasan_check_write+0x14/0x30 ? _raw_spin_trylock+0xbb/0x130 ? __pfx__raw_spin_trylock+0x10/0x10
__x64_sys_mmap+0x135/0x1e0 x64_sys_c
---truncated---

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected kernel package.

Plugin Details

Severity: High

ID: 370763

File Name: unity_linux_UTSA-2026-142481.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 10/22/2026

Updated: 10/22/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.3

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-64582

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 10/22/2026

Vulnerability Publication Date: 8/5/2026

Reference Information

CVE: CVE-2026-64582

Detections

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