CVE-2018-20784
published 2019-02-22CVE-2018-20784: In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in…
PriorityP338critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
4.17%
89.8th percentile
In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.
Affected
17 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| debian | linux | < linux 4.19.16-1 (bookworm) | linux 4.19.16-1 (bookworm) |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 4.19.16-1 | 4.19.16-1 |
| linux | linux_kernel | >= 0 < 4.19.16-1 | 4.19.16-1 |
| linux | linux_kernel | >= 0 < 4.19.16-1 | 4.19.16-1 |
| linux | linux_kernel | >= 0 < 4.19.16-1 | 4.19.16-1 |
| linux | linux_kernel | >= 0 < 4.4.0-170.199 | 4.4.0-170.199 |
| linux | linux_kernel | >= 0 < 4.15.0-62.69 | 4.15.0-62.69 |
| linux | linux_kernel | >= 0 < 4.15.0-60.67 | 4.15.0-60.67 |
| linux | linux_kernel | >= 4.13 < 4.14.93 | 4.14.93 |
| linux | linux_kernel | >= 4.19 < 4.19.15 | 4.19.15 |
| linux | linux_kernel | >= 4.20 < 4.20.2 | 4.20.2 |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux_for_real_time | — | — |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
osv9.8CRITICAL
vendor_debian9.8CRITICAL
vendor_redhat9.8CRITICAL
vendor_ubuntu9.8CRITICAL
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Ubuntu
Linux kernel (Xenial HWE) vulnerabilities
vendor_ubuntu·2019-12-03·CVSS 9.8
CVE-2018-20784 [CRITICAL] Linux kernel (Xenial HWE) vulnerabilities
Title: Linux kernel (Xenial HWE) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
USN-4211-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04
LTS. This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu
14.04 ESM.
Zhipeng Xie discovered that an infinite loop could be triggered in the CFS
Linux kernel process scheduler. A local attacker could possibly use this to
cause a denial of service. (CVE-2018-20784)
Nicolas Waisman discovered that the WiFi driver stack in the Linux kernel
did not properly validate SSID lengths. A physically proximate attacker
could use this to cause a denial of service (system crash).
(CVE-2019-17133)
Nicolas Waisman discovered that the Chelsio T4/T5
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2019-12-03·CVSS 9.8
CVE-2018-20784 [CRITICAL] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Zhipeng Xie discovered that an infinite loop could be triggered in the CFS
Linux kernel process scheduler. A local attacker could possibly use this to
cause a denial of service. (CVE-2018-20784)
Nicolas Waisman discovered that the WiFi driver stack in the Linux kernel
did not properly validate SSID lengths. A physically proximate attacker
could use this to cause a denial of service (system crash).
(CVE-2019-17133)
Nicolas Waisman discovered that the Chelsio T4/T5 RDMA Driver for the Linux
kernel performed DMA from a kernel stack. A local attacker could use this
to cause a denial of service (system crash). (CVE-2019-17075)
Instructions: After a standard system update you need to reboot
Ubuntu
Linux kernel regression
vendor_ubuntu·2019-09-11·CVSS 4.6
[MEDIUM] Linux kernel regression
Title: Linux kernel regression
Summary: USN 4115-1 introduced a regression in the Linux kernel.
USN 4115-1 fixed vulnerabilities in the Linux 4.15 kernel for Ubuntu
18.04 LTS and Ubuntu 16.04 LTS. Unfortunately, as part of the update,
a regression was introduced that caused a kernel crash when handling
fragmented packets in some situations. This update addresses the issue.
We apologize for the inconvenience.
Original advisory details:
Hui Peng and Mathias Payer discovered that the Option USB High Speed driver
in the Linux kernel did not properly validate metadata received from the
device. A physically proximate attacker could use this to cause a denial of
service (system crash). (CVE-2018-19985)
Zhipeng Xie discovered that an infinite loop could triggered in the CFS
Linux kernel proc
Ubuntu
Linux kernel (AWS) vulnerabilities
vendor_ubuntu·2019-09-02·CVSS 3.3
CVE-2018-13053 [LOW] Linux kernel (AWS) vulnerabilities
Title: Linux kernel (AWS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that the alarmtimer implementation in the Linux kernel
contained an integer overflow vulnerability. A local attacker could use
this to cause a denial of service. (CVE-2018-13053)
Wen Xu discovered that the XFS filesystem implementation in the Linux
kernel did not properly track inode validations. An attacker could use this
to construct a malicious XFS image that, when mounted, could cause a denial
of service (system crash). (CVE-2018-13093)
Wen Xu discovered that the f2fs file system implementation in the Linux
kernel did not properly validate metadata. An attacker could use this to
construct a malicious f2fs image that, when mounted, could cause a denial
of serv
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2019-09-02·CVSS 4.6
CVE-2018-19985 [MEDIUM] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Hui Peng and Mathias Payer discovered that the Option USB High Speed driver
in the Linux kernel did not properly validate metadata received from the
device. A physically proximate attacker could use this to cause a denial of
service (system crash). (CVE-2018-19985)
Zhipeng Xie discovered that an infinite loop could be triggered in the CFS
Linux kernel process scheduler. A local attacker could possibly use this to
cause a denial of service. (CVE-2018-20784)
It was discovered that the Intel Wi-Fi device driver in the Linux kernel did
not properly validate certain Tunneled Direct Link Setup (TDLS). A
physically proximate attacker could use this to cause a denial of service
(Wi-Fi disconnec
Red Hat
kernel: infinite loop in update_blocked_averages() in kernel/sched/fair.c leading to denial of service
vendor_redhat·2018-12-28·CVSS 9.8
CVE-2018-20784 [CRITICAL] CWE-835 kernel: infinite loop in update_blocked_averages() in kernel/sched/fair.c leading to denial of service
kernel: infinite loop in update_blocked_averages() in kernel/sched/fair.c leading to denial of service
In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.
The CFS Linux kernel scheduler mishandles handling of leaf cfs_rq's in the kernel/sched/fair.c code, which allows a local unprivileged attacker to cause a denial of service (DoS) by entering an infinite loop in update_blocked_averages() function by inducing a high load on a system. Due to the nature of the flaw, a remote network attack (by initiating a magnitude of remote requests) cannot be fully ruled out.
Package: kernel (Red Hat Enterprise Lin
Debian
CVE-2018-20784: linux - In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's,...
vendor_debian·2018·CVSS 9.8
CVE-2018-20784 [CRITICAL] CVE-2018-20784: linux - In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's,...
In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.
Scope: local
bookworm: resolved (fixed in 4.19.16-1)
bullseye: resolved (fixed in 4.19.16-1)
forky: resolved (fixed in 4.19.16-1)
sid: resolved (fixed in 4.19.16-1)
trixie: resolved (fixed in 4.19.16-1)
GHSA
GHSA-qg2g-rfcv-qffx: In the Linux kernel before 4
ghsa_unreviewed·2022-05-13
CVE-2018-20784 [CRITICAL] CWE-835 GHSA-qg2g-rfcv-qffx: In the Linux kernel before 4
In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.
OSV
linux-lts-xenial, linux-aws vulnerabilities
osv·2019-12-03·CVSS 9.8
CVE-2018-20784 [CRITICAL] linux-lts-xenial, linux-aws vulnerabilities
linux-lts-xenial, linux-aws vulnerabilities
USN-4211-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04
LTS. This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu
14.04 ESM.
Zhipeng Xie discovered that an infinite loop could be triggered in the CFS
Linux kernel process scheduler. A local attacker could possibly use this to
cause a denial of service. (CVE-2018-20784)
Nicolas Waisman discovered that the WiFi driver stack in the Linux kernel
did not properly validate SSID lengths. A physically proximate attacker
could use this to cause a denial of service (system crash).
(CVE-2019-17133)
Nicolas Waisman discovered that the Chelsio T4/T5 RDMA Driver for the Linux
kernel performed DMA from a kernel stack. A l
OSV
linux, linux-aws, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities
osv·2019-12-03·CVSS 9.8
CVE-2018-20784 [CRITICAL] linux, linux-aws, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities
linux, linux-aws, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities
Zhipeng Xie discovered that an infinite loop could be triggered in the CFS
Linux kernel process scheduler. A local attacker could possibly use this to
cause a denial of service. (CVE-2018-20784)
Nicolas Waisman discovered that the WiFi driver stack in the Linux kernel
did not properly validate SSID lengths. A physically proximate attacker
could use this to cause a denial of service (system crash).
(CVE-2019-17133)
Nicolas Waisman discovered that the Chelsio T4/T5 RDMA Driver for the Linux
kernel performed DMA from a kernel stack. A local attacker could use this
to cause a denial of service (system crash). (CVE-2019-17075)
OSV
linux, linux-aws, linux-aws-hwe, linux-azure, linux-gcp, linux-gke-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2 regression
osv·2019-09-11·CVSS 4.6
[MEDIUM] linux, linux-aws, linux-aws-hwe, linux-azure, linux-gcp, linux-gke-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2 regression
linux, linux-aws, linux-aws-hwe, linux-azure, linux-gcp, linux-gke-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2 regression
USN 4115-1 fixed vulnerabilities in the Linux 4.15 kernel for Ubuntu
18.04 LTS and Ubuntu 16.04 LTS. Unfortunately, as part of the update,
a regression was introduced that caused a kernel crash when handling
fragmented packets in some situations. This update addresses the issue.
We apologize for the inconvenience.
Original advisory details:
Hui Peng and Mathias Payer discovered that the Option USB High Speed driver
in the Linux kernel did not properly validate metadata received from the
device. A physically proximate attacker could use this to cause a denial of
service (system crash). (CVE-2018-19985)
Zhipeng Xie discovered that an infinite loop could tr
OSV
linux, linux-azure, linux-gcp, linux-gke-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2 vulnerabilities
osv·2019-09-02·CVSS 4.6
CVE-2018-19985 [MEDIUM] linux, linux-azure, linux-gcp, linux-gke-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2 vulnerabilities
linux, linux-azure, linux-gcp, linux-gke-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2 vulnerabilities
Hui Peng and Mathias Payer discovered that the Option USB High Speed driver
in the Linux kernel did not properly validate metadata received from the
device. A physically proximate attacker could use this to cause a denial of
service (system crash). (CVE-2018-19985)
Zhipeng Xie discovered that an infinite loop could be triggered in the CFS
Linux kernel process scheduler. A local attacker could possibly use this to
cause a denial of service. (CVE-2018-20784)
It was discovered that the Intel Wi-Fi device driver in the Linux kernel did
not properly validate certain Tunneled Direct Link Setup (TDLS). A
physically proximate attacker could use this to cause a denial of service
(Wi-Fi
OSV
linux-aws vulnerabilities
osv·2019-09-02·CVSS 3.3
CVE-2018-13053 [LOW] linux-aws vulnerabilities
linux-aws vulnerabilities
It was discovered that the alarmtimer implementation in the Linux kernel
contained an integer overflow vulnerability. A local attacker could use
this to cause a denial of service. (CVE-2018-13053)
Wen Xu discovered that the XFS filesystem implementation in the Linux
kernel did not properly track inode validations. An attacker could use this
to construct a malicious XFS image that, when mounted, could cause a denial
of service (system crash). (CVE-2018-13093)
Wen Xu discovered that the f2fs file system implementation in the Linux
kernel did not properly validate metadata. An attacker could use this to
construct a malicious f2fs image that, when mounted, could cause a denial
of service (system crash). (CVE-2018-13096, CVE-2018-13097, CVE-2018-13098,
CVE-2018-1309
OSV
CVE-2018-20784: In the Linux kernel before 4
osv·2019-02-22·CVSS 9.8
CVE-2018-20784 [CRITICAL] CVE-2018-20784: In the Linux kernel before 4
In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2018-20784 kernel: infinite loop in update_blocked_averages() in kernel/sched/fair.c leading to denial of service [fedora-all]
bugzilla·2019-02-25·CVSS 9.8
CVE-2018-20784 [CRITICAL] CVE-2018-20784 kernel: infinite loop in update_blocked_averages() in kernel/sched/fair.c leading to denial of service [fedora-all]
CVE-2018-20784 kernel: infinite loop in update_blocked_averages() in kernel/sched/fair.c leading to denial of service [fedora-all]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of fedora-all.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.
Bugzilla
CVE-2018-20784 kernel: infinite loop in update_blocked_averages() in kernel/sched/fair.c leading to denial of service
bugzilla·2019-02-25·CVSS 9.8
CVE-2018-20784 [CRITICAL] CVE-2018-20784 kernel: infinite loop in update_blocked_averages() in kernel/sched/fair.c leading to denial of service
CVE-2018-20784 kernel: infinite loop in update_blocked_averages() in kernel/sched/fair.c leading to denial of service
The CFS Linux kernel scheduler mishandles handling of leaf cfs_rq's in the kernel/sched/fair.c code, which allows a local unprivileged attacker to cause a denial of service (DoS) by entiring the infinite loop in update_blocked_averages() function by inducing a high load on a system. Due to the nature of the flaw, a remote network attack (by initiating a magnitude of remote requests) cannot be fully ruled out, although we believe it is unlikely.
References:
https://lore.kernel.org/lkml/[email protected]/T/#u
An upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c40f7d74c741a907cfaeb73a7697081
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c40f7d74c741a907cfaeb73a7697081881c497d0https://access.redhat.com/errata/RHSA-2019:1959https://access.redhat.com/errata/RHSA-2019:1971https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.2https://github.com/torvalds/linux/commit/c40f7d74c741a907cfaeb73a7697081881c497d0https://usn.ubuntu.com/4115-1/https://usn.ubuntu.com/4118-1/https://usn.ubuntu.com/4211-1/https://usn.ubuntu.com/4211-2/http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c40f7d74c741a907cfaeb73a7697081881c497d0https://access.redhat.com/errata/RHSA-2019:1959https://access.redhat.com/errata/RHSA-2019:1971https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.2https://github.com/torvalds/linux/commit/c40f7d74c741a907cfaeb73a7697081881c497d0https://usn.ubuntu.com/4115-1/https://usn.ubuntu.com/4118-1/https://usn.ubuntu.com/4211-1/https://usn.ubuntu.com/4211-2/
2019-02-22
Published