Description
Since Linux kernel version 3.2, the mremap() syscall performs TLB flushes after dropping pagetable locks. If a syscall such as ftruncate() removes entries from the pagetables of a task that is in the middle of mremap(), a stale TLB entry can remain for a short time that permits access to a physical page after it has been released back to the page allocator and reused. This is fixed in the following kernel versions: 4.9.135, 4.14.78, 4.18.16, 4.19.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 4.18.20-1 | — |
| Debian 13 | linux | 4.18.20-1 | — |
| Debian 12 | linux | 4.18.20-1 | — |
| Debian 8 | linux | 3.16.64-1 | DLA-1731-1 |
| Debian 8 | linux-4.9 | 4.9.144-3.1~deb8u1 | DLA-1715-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-azure-fde | No fix yet | — |
| Ubuntu 18.04 LTS | linux | 4.15.0-44.47 | USN-3871-1 |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1032.34 | USN-3871-3 |
| Ubuntu 18.04 LTS | linux-azure | 4.15.0-1037.39 | USN-3871-5 |
| Ubuntu 18.04 LTS | linux-gcp | 4.15.0-1027.28 | USN-3871-3 |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1029.29 | USN-3871-3 |
| Ubuntu 18.04 LTS | linux-oem | 4.15.0-1033.38 | USN-3871-3 |
| Ubuntu 18.04 LTS | linux-raspi2 | 4.15.0-1031.33 | USN-3871-3 |
| Ubuntu 18.04 LTS | linux-snapdragon | 4.15.0-1053.57 | — |
| Ubuntu 16.04 LTS | linux | 4.4.0-142.168 | — |
| Ubuntu 16.04 LTS | linux-aws | 4.4.0-1075.85 | — |
| Ubuntu 16.04 LTS | linux-aws-hwe | 4.15.0-1032.34~16.04.1 | USN-3871-4 |
| Ubuntu 16.04 LTS | linux-azure | 4.15.0-1037.39~16.04.1 | USN-3871-5 |
| Ubuntu 16.04 LTS | linux-gcp | 4.15.0-1027.28~16.04.1 | USN-3871-4 |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-45.48~16.04.1 | USN-3871-4 |
| Ubuntu 16.04 LTS | linux-kvm | 4.4.0-1040.46 | — |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1103.111 | — |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1107.112 | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | linux | 3.13.0-165.215 | USN-3880-1 |
| Ubuntu 14.04 LTS | linux-aws | 4.4.0-1038.41 | — |
| Ubuntu 14.04 LTS | linux-azure | 4.15.0-1037.39~14.04.2 | USN-3871-5 |
| Ubuntu 14.04 LTS | linux-lts-xenial | 4.4.0-142.168~14.04.1 | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | 4.4.0-1008.10 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | kernel +15 | 3.10.0-1062.el7 | RHSA-2019:2029, RHSA-2019:0831 |
| RHEL 7 | kernel-alt | 4.14.0-115.7.1.el7a | RHSA-2019:0831 |
| RHEL 7 | kernel-rt +10 | 3.10.0-1062.rt56.1022.el7 | RHSA-2019:2043 |
| RHEL 7 | perf +3 | 3.10.0-957.43.1.el7 | RHSA-2020:0179, RHSA-2019:2029, RHSA-2019:0831 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7.6 EUS | perf +19 | 3.10.0-957.43.1.el7 | RHSA-2020:0179 |
| RHEL 7.5 EUS | perf +18 | 3.10.0-862.46.1.el7 | RHSA-2020:0036 |
| RHEL 7.4 TUS | perf +11 | 3.10.0-693.62.1.el7 | RHSA-2020:0103 |
| RHEL 7.4 E4S | perf +13 | 3.10.0-693.62.1.el7 | RHSA-2020:0103 |
| RHEL 7.4 AUS | perf +11 | 3.10.0-693.62.1.el7 | RHSA-2020:0103 |
| Red Hat MRG 2 | kernel-rt +10 | 1:3.10.0-693.62.1.rt56.659.el6rt | RHSA-2020:0100 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 | kernel-azure +2 | 4.12.14-5.19.1 | SUSE-SU-2019:0150-1 |
| SLES 15 | kernel-docs +6 | 4.12.14-25.28.1 | SUSE-SU-2019:0224-1 |
| SLES 12 SP4 | kernel-azure +2 | 4.12.14-6.6.2 | SUSE-SU-2019:0222-1 |
| SLES 12 SP4 | kernel-docs +3 | 4.12.14-95.3.1 | SUSE-SU-2018:4069-1 |
| SLES 12 SP4 | kernel-obs-build | 4.12.14-95.3.2 | SUSE-SU-2018:4069-1 |
| SLES 12 SP3 | kernel-azure | 4.4.162-4.19.2 | SUSE-SU-2019:0095-1 |
| SLES 12 SP3 | kernel-docs +4 | 4.4.162-94.69.2 | SUSE-SU-2018:3689-1 |
| SLES 12 SP3 | kernel-syms-azure +1 | 4.4.162-4.19.1 | SUSE-SU-2019:0095-1 |
| SLES 12 SP3 | lttng-modules | 2.7.1-8.6.1 | SUSE-SU-2018:3689-1 |
| SLES 12 SP2 | kernel-syms +2 | 4.4.121-92.101.1 | SUSE-SU-2019:0439-1 |
| SLES 12 SP2 | kgraft-patch-SLE12-SP2_Update_27 | 1-3.3.1 | SUSE-SU-2019:0439-1 |
| SLES 12 SP1 | kernel-xen +3 | 3.12.74-60.64.110.1 | SUSE-SU-2019:1289-1 |
| SLES 12 SP1 | kgraft-patch-SLE12-SP1_Update_33 | 1-2.3.1 | SUSE-SU-2019:1289-1 |
| SLES 12 SP1 | lttng-modules | 2.7.0-4.4.1 | SUSE-SU-2019:1289-1 |
Show 16 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | kernel-ec2 | 3.12.74-60.64.110.1 | SUSE-SU-2019:1289-1 |
| SLES 11 SP4 | kernel-ec2 +9 | 3.0.101-108.81.1 | SUSE-SU-2018:3746-1 |
| SLES 11 SP3 | kernel-ec2 +7 | 3.0.101-0.47.106.59.1 | SUSE-SU-2019:13937-1 |
| SLES for SAP 12 SP4 | kernel-azure +2 | 4.12.14-6.6.2 | SUSE-SU-2019:0222-1 |
| SLES for SAP 12 SP4 | kernel-syms +2 | 4.12.14-95.3.1 | SUSE-SU-2018:4069-1 |
| SLES for SAP 12 SP3 | kernel-azure | 4.4.162-4.19.2 | SUSE-SU-2019:0095-1 |
| SLES for SAP 12 SP3 | kernel-syms +2 | 4.4.162-94.69.2 | SUSE-SU-2018:3689-1 |
| SLES for SAP 12 SP3 | kernel-syms-azure +1 | 4.4.162-4.19.1 | SUSE-SU-2019:0095-1 |
| SLES for SAP 12 SP3 | lttng-modules | 2.7.1-8.6.1 | SUSE-SU-2018:3689-1 |
| SLES for SAP 12 SP2 | kernel-syms +2 | 4.4.121-92.101.1 | SUSE-SU-2019:0439-1 |
| SLES for SAP 12 SP2 | kgraft-patch-SLE12-SP2_Update_27 | 1-3.3.1 | SUSE-SU-2019:0439-1 |
| SLES for SAP 12 SP1 | kernel-xen +3 | 3.12.74-60.64.110.1 | SUSE-SU-2019:1289-1 |
| SLES for SAP 12 SP1 | kgraft-patch-SLE12-SP1_Update_33 | 1-2.3.1 | SUSE-SU-2019:1289-1 |
| SLES for SAP 12 SP1 | lttng-modules | 2.7.0-4.4.1 | SUSE-SU-2019:1289-1 |
| SLES for SAP 11 SP4 | kernel-ec2 +8 | 3.0.101-108.81.1 | SUSE-SU-2018:3746-1 |
| SLE Real Time 12 SP3 | kernel-rt +3 | 4.4.162-3.29.1 | SUSE-SU-2018:3773-1 |
| SLE Real Time 11 SP4 | kernel-rt +3 | 3.0.101.rt130-69.39.1 | SUSE-SU-2018:3869-1 |
| SLE Live Patching 15 | kernel-default | 4.12.14-25.28.1 | SUSE-SU-2019:0224-1 |
| SLE Live Patching 15 | kernel-livepatch-SLE15_Update_8 | 1-1.3.1 | SUSE-SU-2019:0224-1 |
| SLE Live Patching 12 SP4 | kgraft-patch-SLE12-SP4_Update_1 | 1-7.1 | SUSE-SU-2018:4072-1 |
| SLE Live Patching 12 SP3 | kgraft-patch-SLE12-SP3_Update_21 | 1-4.5.2 | SUSE-SU-2018:3688-1 |
| SUSE OpenStack Cloud 7 | kernel-syms +2 | 4.4.121-92.101.1 | SUSE-SU-2019:0439-1 |
| SUSE OpenStack Cloud 7 | kgraft-patch-SLE12-SP2_Update_27 | 1-3.3.1 | SUSE-SU-2019:0439-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | kernel-ec2 +6 | 3.0.101-0.47.106.59.1 | SUSE-SU-2019:13937-1 |
| SUSE Enterprise Storage 4 | kernel-syms +2 | 4.4.121-92.101.1 | SUSE-SU-2019:0439-1 |
| SUSE Enterprise Storage 4 | kgraft-patch-SLE12-SP2_Update_27 | 1-3.3.1 | SUSE-SU-2019:0439-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | dtrace-modules-3.8.13-118.46.1.el6uek | 0.4.5-3.el6 | ELSA-2020-5706 |
| Oracle Linux 7 | dtrace-modules-3.8.13-118.46.1.el7uek | 0.4.5-3.el7 | ELSA-2020-5706 |
| Oracle Linux 7 | kernel-uek +5 | 3.8.13-118.46.1.el7uek | ELSA-2020-5708, ELSA-2020-5706 |
| Oracle Linux 7 | perf +12 | 3.10.0-1062.el7 | ELSA-2019-2029 |
Advisories 31
- RHSA-2020:0103 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Aug 26, 2026
- RHSA-2020:0100 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Aug 26, 2026
- RHSA-2020:0179 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- RHSA-2020:0036 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- RHSA-2019:2043 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- RHSA-2019:2029 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- RHSA-2019:0831 Red Hat Security Advisory: kernel-alt security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- USN-3871-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3880-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-1731-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1715-1 linux-4.9 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-3871-3 linux-aws, linux-gcp, linux-kvm, linux-oem, linux-raspi2 vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-3871-4 linux-hwe, linux-aws-hwe, linux-gcp vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-3871-5 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2019:0222-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:0150-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:0224-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:1289-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:3688-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:3689-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:4072-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:3746-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:0439-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · May 2, 2025
- SUSE-SU-2018:3773-1 Security update for the Linux RT Kernel SUSE / openSUSE Security Updates · May 2, 2025
- SUSE-SU-2019:0095-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · May 2, 2025
- SUSE-SU-2018:4069-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · May 2, 2025
- SUSE-SU-2018:3869-1 Security update for the Linux RT Kernel SUSE / openSUSE Security Updates · May 2, 2025
- SUSE-SU-2019:13937-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · May 2, 2025
- ELSA-2020-5706 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jun 4, 2020
- ELSA-2020-5708 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jun 3, 2020
- ELSA-2019-2029 Important: kernel security, bug fix, and enhancement update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Aug 13, 2019
References
- http://packetstormsecurity.com/files/150001/Linux-mremap-TLB-Flush-Too-Late.html
- USN-3835-1 vendor-advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.16
- USN-3880-1 vendor-advisory
- USN-3871-5 vendor-advisory
- USN-3871-4 vendor-advisory
- [oss-security] 20181029 Linux kernel: TLB flush happens too late on mremap (CVE-2018-18281; fixed in 4.9.135, 4.14.78, 4.18.16, 4.19) mailing-list
- USN-3880-2 vendor-advisory
- USN-3832-1 vendor-advisory
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eb66ae030829605d61fbef1909ce310e29f78821
- 105761 vdb-entry
- USN-3871-1 vendor-advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.78
- 106503 vdb-entry
- USN-3871-3 vendor-advisory
- https://bugs.chromium.org/p/project-zero/issues/detail?id=1695
- [debian-lts-announce] 20190315 [SECURITY] [DLA 1715-1] linux-4.9 security update mailing-list
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.135
- [debian-lts-announce] 20190327 [SECURITY] [DLA 1731-1] linux security update mailing-list
- [debian-lts-announce] 20190401 [SECURITY] [DLA 1731-2] linux regression update mailing-list
- RHSA-2019:0831 vendor-advisory
- RHSA-2019:2043 vendor-advisory
- RHSA-2019:2029 vendor-advisory
- RHSA-2020:0036 vendor-advisory
- RHSA-2020:0100 vendor-advisory
- RHSA-2020:0103 vendor-advisory
- RHSA-2020:0179 vendor-advisory