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Fencer Vulns
high 7.8

CVE-2026-64582 json

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

published 2026-08-05 3 mo ago modified 2026-10-19 20 d ago also EUVD-2026-53329

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

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 1→0 */ 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---

Patch / fix

  • Linux Linux 5.10.265, 5.15.216, 6.1.183, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2
  • linux Debian 12 6.1.187-1
  • linux Debian 13 6.12.100-1
  • linux Debian 14 7.1.5-1
  • linux-6.12 Debian 12 6.12.100-1~deb12u1

debian advisories DEBIAN-CVE-2026-64582

  • linux Ubuntu 22.04 LTS 5.15.0-198.208
  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-38.38
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79

ubuntu advisories UBUNTU-CVE-2026-64582

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-rt RHEL 8 4.18.0-553.166.1.rt7.507.el8_10
  • kernel-rt-kvm RHEL 8 4.18.0-553.166.1.rt7.507.el8_10
  • kernel-rt-core RHEL 8 4.18.0-553.166.1.rt7.507.el8_10
  • kernel-rt-modules RHEL 8 4.18.0-553.166.1.rt7.507.el8_10
  • kernel-rt-debug-kvm RHEL 8 4.18.0-553.166.1.rt7.507.el8_10
  • kernel-rt-debug-core RHEL 8 4.18.0-553.166.1.rt7.507.el8_10
  • kernel-rt-debug-modules RHEL 8 4.18.0-553.166.1.rt7.507.el8_10
  • kernel-rt-modules-extra RHEL 8 4.18.0-553.166.1.rt7.507.el8_10

red hat advisories RHSA-2026:77219RHSA-2026:77301RHSA-2026:77218RHSA-2026:77217RHSA-2026:77216RHSA-2026:70403

  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.81.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.81.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-obs-build SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1
  • kernel-default-base SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1.150700.17.45.1

suse advisories SUSE-SU-2026:4254-1SUSE-SU-2026:23887-1SUSE-SU-2026:23902-1SUSE-SU-2026:23897-1SUSE-SU-2026:23881-1SUSE-SU-2026:4282-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.38.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.38.1

opensuse advisories openSUSE-SU-2026:21910-1openSUSE-SU-2026:11476-1

  • kernel AlmaLinux 8 4.18.0-553.166.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.166.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.166.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.166.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.166.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.166.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.166.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.166.1.el8_10

almalinux advisories ALSA-2026:70402ALSA-2026:70403ALSA-2026:68570

  • kernel-rt Rocky Linux 8 4.18.0-553.166.1.rt7.507.el8_10
  • kernel Rocky Linux 8 4.18.0-553.166.1.el8_10
  • kernel Rocky Linux 9 5.14.0-687.49.1.el9_8

rocky linux advisories RLSA-2026:70403RLSA-2026:70402RLSA-2026:68570

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-64582 updated cvss 7.8

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

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.6) libperf 5.14.0-570.147.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.147.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.147.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.147.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.147.1.el9_6
    fixed: vendor fix RHSA-2026:77219
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.49.1.el9_8, perf 5.14.0-687.49.1.el9_8, rtla 5.14.0-687.49.1.el9_8, python3-perf 5.14.0-687.49.1.el9_8, kernel-devel-matched 5.14.0-687.49.1.el9_8, kernel-64k-devel-matched 5.14.0-687.49.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:68570
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) rv 5.14.0-427.154.1.el9_4, perf 5.14.0-427.154.1.el9_4, rtla 5.14.0-427.154.1.el9_4, kernel-devel-matched 5.14.0-427.154.1.el9_4, kernel-64k-devel-matched 5.14.0-427.154.1.el9_4, kernel-debug-devel-matched 5.14.0-427.154.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:77218
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) rv 5.14.0-570.147.1.el9_6, perf 5.14.0-570.147.1.el9_6, rtla 5.14.0-570.147.1.el9_6, python3-perf 5.14.0-570.147.1.el9_6, kernel-devel-matched 5.14.0-570.147.1.el9_6, kernel-64k-devel-matched 5.14.0-570.147.1.el9_6, +7 more
    fixed: vendor fix RHSA-2026:77219
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.166.1.el8_10, kernel 4.18.0-553.166.1.el8_10, bpftool 4.18.0-553.166.1.el8_10, kernel-core 4.18.0-553.166.1.el8_10, kernel-tools 4.18.0-553.166.1.el8_10, python3-perf 4.18.0-553.166.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:70402
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.49.1.el9_8, kernel-64k 5.14.0-687.49.1.el9_8, kernel-core 5.14.0-687.49.1.el9_8, kernel-tools 5.14.0-687.49.1.el9_8, kernel-modules 5.14.0-687.49.1.el9_8, kernel-64k-core 5.14.0-687.49.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:68570
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) perf 4.18.0-305.211.1.el8_4, kernel 4.18.0-305.211.1.el8_4, bpftool 4.18.0-305.211.1.el8_4, kernel-core 4.18.0-305.211.1.el8_4, kernel-tools 4.18.0-305.211.1.el8_4, python3-perf 4.18.0-305.211.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:77217
show 18 more
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.220.1.el8_6, kernel 4.18.0-372.220.1.el8_6, bpftool 4.18.0-372.220.1.el8_6, kernel-core 4.18.0-372.220.1.el8_6, kernel-tools 4.18.0-372.220.1.el8_6, python3-perf 4.18.0-372.220.1.el8_6, +8 more
    fixed: vendor fix RHSA-2026:77216
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.172.1.el8_8, kernel 4.18.0-477.172.1.el8_8, bpftool 4.18.0-477.172.1.el8_8, kernel-core 4.18.0-477.172.1.el8_8, kernel-tools 4.18.0-477.172.1.el8_8, python3-perf 4.18.0-477.172.1.el8_8, +9 more
    fixed: vendor fix RHSA-2026:77301
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool 7.3.0-427.154.1.el9_4, kernel 5.14.0-427.154.1.el9_4, kernel-64k 5.14.0-427.154.1.el9_4, kernel-core 5.14.0-427.154.1.el9_4, kernel-tools 5.14.0-427.154.1.el9_4, python3-perf 5.14.0-427.154.1.el9_4, +28 more
    fixed: vendor fix RHSA-2026:77218
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel 5.14.0-570.147.1.el9_6, kernel-64k 5.14.0-570.147.1.el9_6, kernel-core 5.14.0-570.147.1.el9_6, kernel-tools 5.14.0-570.147.1.el9_6, kernel-modules 5.14.0-570.147.1.el9_6, kernel-64k-core 5.14.0-570.147.1.el9_6, +27 more
    fixed: vendor fix RHSA-2026:77219
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) perf 4.18.0-305.211.1.el8_4, kernel 4.18.0-305.211.1.el8_4, bpftool 4.18.0-305.211.1.el8_4, kernel-core 4.18.0-305.211.1.el8_4, kernel-tools 4.18.0-305.211.1.el8_4, python3-perf 4.18.0-305.211.1.el8_4, +15 more
    fixed: vendor fix RHSA-2026:77217
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) perf 4.18.0-372.220.1.el8_6, kernel 4.18.0-372.220.1.el8_6, bpftool 4.18.0-372.220.1.el8_6, kernel-core 4.18.0-372.220.1.el8_6, kernel-tools 4.18.0-372.220.1.el8_6, python3-perf 4.18.0-372.220.1.el8_6, +15 more
    fixed: vendor fix RHSA-2026:77216
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.172.1.el8_8, kernel 4.18.0-477.172.1.el8_8, bpftool 4.18.0-477.172.1.el8_8, kernel-core 4.18.0-477.172.1.el8_8, kernel-tools 4.18.0-477.172.1.el8_8, python3-perf 4.18.0-477.172.1.el8_8, +8 more
    fixed: vendor fix RHSA-2026:77301
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.49.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.49.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.49.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.49.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.49.1.el9_8
    fixed: vendor fix RHSA-2026:68570
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.166.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.166.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.166.1.el8_10
    fixed: vendor fix RHSA-2026:70402
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-kvm 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-core 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-modules 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-debug-kvm 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-debug-core 4.18.0-553.166.1.rt7.507.el8_10, +4 more
    fixed: vendor fix RHSA-2026:70403
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.49.1.el9_8, kernel-rt-64k 5.14.0-687.49.1.el9_8, kernel-rt-core 5.14.0-687.49.1.el9_8, kernel-rt-modules 5.14.0-687.49.1.el9_8, kernel-rt-64k-core 5.14.0-687.49.1.el9_8, kernel-rt-debug-core 5.14.0-687.49.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:68570
  • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt 5.14.0-427.154.1.el9_4, kernel-rt-core 5.14.0-427.154.1.el9_4, kernel-rt-modules 5.14.0-427.154.1.el9_4, kernel-rt-debug-core 5.14.0-427.154.1.el9_4, kernel-rt-modules-core 5.14.0-427.154.1.el9_4, kernel-rt-debug-modules 5.14.0-427.154.1.el9_4, +4 more
    fixed: vendor fix RHSA-2026:77218
  • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt 5.14.0-570.147.1.el9_6, kernel-rt-64k 5.14.0-570.147.1.el9_6, kernel-rt-core 5.14.0-570.147.1.el9_6, kernel-rt-modules 5.14.0-570.147.1.el9_6, kernel-rt-64k-core 5.14.0-570.147.1.el9_6, kernel-rt-debug-core 5.14.0-570.147.1.el9_6, +14 more
    fixed: vendor fix RHSA-2026:77219
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.49.1.el9_8, kernel-rt-core 5.14.0-687.49.1.el9_8, kernel-rt-modules 5.14.0-687.49.1.el9_8, kernel-rt-debug-core 5.14.0-687.49.1.el9_8, kernel-rt-modules-core 5.14.0-687.49.1.el9_8, kernel-rt-debug-modules 5.14.0-687.49.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:68570
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt 5.14.0-427.154.1.el9_4, kernel-rt-kvm 5.14.0-427.154.1.el9_4, kernel-rt-core 5.14.0-427.154.1.el9_4, kernel-rt-modules 5.14.0-427.154.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.154.1.el9_4, kernel-rt-debug-core 5.14.0-427.154.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:77218
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt 5.14.0-570.147.1.el9_6, kernel-rt-kvm 5.14.0-570.147.1.el9_6, kernel-rt-core 5.14.0-570.147.1.el9_6, kernel-rt-modules 5.14.0-570.147.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.147.1.el9_6, kernel-rt-debug-core 5.14.0-570.147.1.el9_6, +6 more
    fixed: vendor fix RHSA-2026:77219
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-core 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-modules 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-debug-core 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-debug-modules 4.18.0-553.166.1.rt7.507.el8_10, kernel-rt-modules-extra 4.18.0-553.166.1.rt7.507.el8_10, +2 more
    fixed: vendor fix RHSA-2026:70403
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
23 d ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.