CVE-2021-47506
published 2024-05-24CVE-2021-47506: In the Linux kernel, the following vulnerability has been resolved: nfsd: fix use-after-free due to delegation race A delegation break could arrive as soon as…
PriorityP338high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.26%
17.7th percentile
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix use-after-free due to delegation race
A delegation break could arrive as soon as we've called vfs_setlease. A
delegation break runs a callback which immediately (in
nfsd4_cb_recall_prepare) adds the delegation to del_recall_lru. If we
then exit nfs4_set_delegation without hashing the delegation, it will be
freed as soon as the callback is done with it, without ever being
removed from del_recall_lru.
Symptoms show up later as use-after-free or list corruption warnings,
usually in the laundromat thread.
I suspect aba2072f4523 "nfsd: grant read delegations to clients holding
writes" made this bug easier to hit, but I looked as far back as v3.0
and it looks to me it already had the same problem. So I'm not sure
where the bug was introduced; it may have been there from the beginning.
Affected
28 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 5.15.15-1 (bookworm) | linux 5.15.15-1 (bookworm) |
| linux | linux | — | — |
| linux | linux | >= dff1399f8addf7129c49bb2227469da79cc30b47 < 04a8d07f3d58308b92630045560799a3faa3ebce | 04a8d07f3d58308b92630045560799a3faa3ebce |
| linux | linux | >= dff1399f8addf7129c49bb2227469da79cc30b47 < 348714018139c39533c55661a0c7c990671396b4 | 348714018139c39533c55661a0c7c990671396b4 |
| linux | linux | >= dff1399f8addf7129c49bb2227469da79cc30b47 < 33645d3e22720cac1e4548f8fef57bf0649536ee | 33645d3e22720cac1e4548f8fef57bf0649536ee |
| linux | linux | >= dff1399f8addf7129c49bb2227469da79cc30b47 < 2becaa990b93cbd2928292c0b669d3abb6cf06d4 | 2becaa990b93cbd2928292c0b669d3abb6cf06d4 |
| linux | linux | >= dff1399f8addf7129c49bb2227469da79cc30b47 < e0759696de6851d7536efddfdd2dfed4c4df1f09 | e0759696de6851d7536efddfdd2dfed4c4df1f09 |
| linux | linux | >= dff1399f8addf7129c49bb2227469da79cc30b47 < eeb0711801f5e19ef654371b627682aed3b11373 | eeb0711801f5e19ef654371b627682aed3b11373 |
| linux | linux | >= dff1399f8addf7129c49bb2227469da79cc30b47 < 148c816f10fd11df27ca6a9b3238cdd42fa72cd3 | 148c816f10fd11df27ca6a9b3238cdd42fa72cd3 |
| linux | linux | >= dff1399f8addf7129c49bb2227469da79cc30b47 < 548ec0805c399c65ed66c6641be467f717833ab5 | 548ec0805c399c65ed66c6641be467f717833ab5 |
| linux | linux_kernel | < 4.4.296 | 4.4.296 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 5.10.92-1 | 5.10.92-1 |
| linux | linux_kernel | >= 0 < 5.15.15-1 | 5.15.15-1 |
| linux | linux_kernel | >= 0 < 5.15.15-1 | 5.15.15-1 |
| linux | linux_kernel | >= 0 < 5.15.15-1 | 5.15.15-1 |
| linux | linux_kernel | >= 0 < 4.4.0-278.312 | 4.4.0-278.312 |
| linux | linux_kernel | >= 0 < 4.4.0-268.302 | 4.4.0-268.302 |
| linux | linux_kernel | >= 0 < 4.15.0-247.259 | 4.15.0-247.259 |
| linux | linux_kernel | >= 0 < 5.4.0-218.238 | 5.4.0-218.238 |
| linux | linux_kernel | >= 0 < 5.15.0-141.151 | 5.15.0-141.151 |
| linux | linux_kernel | >= 0 < 6.8.0-59.61 | 6.8.0-59.61 |
| linux | linux_kernel | >= 4.10 < 4.14.259 | 4.14.259 |
| linux | linux_kernel | >= 4.15 < 4.19.222 | 4.19.222 |
| linux | linux_kernel | >= 4.20 < 5.4.168 | 5.4.168 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_debian7.8HIGH
vendor_redhat7.8HIGH
vendor_ubuntu7.8HIGH
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Ubuntu
Kernel Live Patch Security Notice
vendor_ubuntu·2025-05-29·CVSS 7.8
CVE-2022-0995 [HIGH] Kernel Live Patch Security Notice
Title: Kernel Live Patch Security Notice
Summary: Several security issues were fixed in the kernel.
In the Linux kernel, the following vulnerability has been
resolved: nfsd: fix use-after-free due to delegation race A delegation
break could arrive as soon as we've called vfs_setlease. A delegation break
runs a callback which immediately (in nfsd4_cb_recall_prepare) adds the
delegation to del_recall_lru. If we then exit nfs4_set_delegation without
hashing the delegation, it will be freed as soon as the callback is done
with it, without ever being removed from del_recall_lru. Symptoms show up
later as use-after-free or list corruption warnings, usually in the
laundromat thread. I suspect aba2072f4523 'nfsd: grant read delegations to
clients holding writes' made this bug easier to hit, but
Ubuntu
Linux kernel (Xenial HWE) vulnerabilities
vendor_ubuntu·2025-05-13·CVSS 7.8
CVE-2024-56650 [HIGH] Linux kernel (Xenial HWE) vulnerabilities
Title: Linux kernel (Xenial HWE) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Demi Marie Obenour and Simon Gaiser discovered that several Xen para-
virtualization device frontends did not properly restrict the access rights
of device backends. An attacker could possibly use a malicious Xen backend
to gain access to memory pages of a guest VM or cause a denial of service
in the guest. (CVE-2022-23041)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- GPU drivers;
- IIO subsystem;
- Media drivers;
- Network drivers;
- SCSI subsystem;
- SPI subsystem;
- USB Gadget drivers;
- Ceph distributed
Ubuntu
Linux kernel (FIPS) vulnerabilities
vendor_ubuntu·2025-05-12·CVSS 7.8
CVE-2024-56650 [HIGH] Linux kernel (FIPS) vulnerabilities
Title: Linux kernel (FIPS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Demi Marie Obenour and Simon Gaiser discovered that several Xen para-
virtualization device frontends did not properly restrict the access rights
of device backends. An attacker could possibly use a malicious Xen backend
to gain access to memory pages of a guest VM or cause a denial of service
in the guest. (CVE-2022-23041)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- GPU drivers;
- IIO subsystem;
- Media drivers;
- Network drivers;
- SCSI subsystem;
- SPI subsystem;
- USB Gadget drivers;
- Ceph distributed file
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2025-05-12·CVSS 7.8
CVE-2024-56650 [HIGH] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Demi Marie Obenour and Simon Gaiser discovered that several Xen para-
virtualization device frontends did not properly restrict the access rights
of device backends. An attacker could possibly use a malicious Xen backend
to gain access to memory pages of a guest VM or cause a denial of service
in the guest. (CVE-2022-23041)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- GPU drivers;
- IIO subsystem;
- Media drivers;
- Network drivers;
- SCSI subsystem;
- SPI subsystem;
- USB Gadget drivers;
- Ceph distributed file system;
Ubuntu
Linux kernel (AWS) vulnerabilities
vendor_ubuntu·2025-05-12·CVSS 7.8
CVE-2023-52741 [HIGH] Linux kernel (AWS) vulnerabilities
Title: Linux kernel (AWS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Demi Marie Obenour and Simon Gaiser discovered that several Xen para-
virtualization device frontends did not properly restrict the access rights
of device backends. An attacker could possibly use a malicious Xen backend
to gain access to memory pages of a guest VM or cause a denial of service
in the guest. (CVE-2022-23041)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- GPU drivers;
- IIO subsystem;
- Media drivers;
- Network drivers;
- SCSI subsystem;
- SPI subsystem;
- USB Gadget drivers;
- Ceph distributed file s
Red Hat
kernel: nfsd: fix use-after-free due to delegation race
vendor_redhat·2024-05-24·CVSS 7.8
CVE-2021-47506 [HIGH] CWE-416 kernel: nfsd: fix use-after-free due to delegation race
kernel: nfsd: fix use-after-free due to delegation race
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix use-after-free due to delegation race
A delegation break could arrive as soon as we've called vfs_setlease. A
delegation break runs a callback which immediately (in
nfsd4_cb_recall_prepare) adds the delegation to del_recall_lru. If we
then exit nfs4_set_delegation without hashing the delegation, it will be
freed as soon as the callback is done with it, without ever being
removed from del_recall_lru.
Symptoms show up later as use-after-free or list corruption warnings,
usually in the laundromat thread.
I suspect aba2072f4523 "nfsd: grant read delegations to clients holding
writes" made this bug easier to hit, but I looked as far back as v3.0
and it looks to
Debian
CVE-2021-47506: linux - In the Linux kernel, the following vulnerability has been resolved: nfsd: fix u...
vendor_debian·2021·CVSS 7.8
CVE-2021-47506 [HIGH] CVE-2021-47506: linux - In the Linux kernel, the following vulnerability has been resolved: nfsd: fix u...
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix use-after-free due to delegation race A delegation break could arrive as soon as we've called vfs_setlease. A delegation break runs a callback which immediately (in nfsd4_cb_recall_prepare) adds the delegation to del_recall_lru. If we then exit nfs4_set_delegation without hashing the delegation, it will be freed as soon as the callback is done with it, without ever being removed from del_recall_lru. Symptoms show up later as use-after-free or list corruption warnings, usually in the laundromat thread. I suspect aba2072f4523 "nfsd: grant read delegations to clients holding writes" made this bug easier to hit, but I looked as far back as v3.0 and it looks to me it already had the same problem. So I'm not sure where
OSV
Kernel Live Patch Security Notice
osv·2025-05-29·CVSS 7.8
[HIGH] Kernel Live Patch Security Notice
Kernel Live Patch Security Notice
In the Linux kernel, the following vulnerability has been
resolved: nfsd: fix use-after-free due to delegation race A delegation
break could arrive as soon as we've called vfs_setlease. A delegation break
runs a callback which immediately (in nfsd4_cb_recall_prepare) adds the
delegation to del_recall_lru. If we then exit nfs4_set_delegation without
hashing the delegation, it will be freed as soon as the callback is done
with it, without ever being removed from del_recall_lru. Symptoms show up
later as use-after-free or list corruption warnings, usually in the
laundromat thread. I suspect aba2072f4523 'nfsd: grant read delegations to
clients holding writes' made this bug easier to hit, but I looked as far
back as v3.0 and it looks to me it already had the
OSV
linux-lts-xenial vulnerabilities
osv·2025-05-13·CVSS 7.8
CVE-2022-23041 [HIGH] linux-lts-xenial vulnerabilities
linux-lts-xenial vulnerabilities
Demi Marie Obenour and Simon Gaiser discovered that several Xen para-
virtualization device frontends did not properly restrict the access rights
of device backends. An attacker could possibly use a malicious Xen backend
to gain access to memory pages of a guest VM or cause a denial of service
in the guest. (CVE-2022-23041)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- GPU drivers;
- IIO subsystem;
- Media drivers;
- Network drivers;
- SCSI subsystem;
- SPI subsystem;
- USB Gadget drivers;
- Ceph distributed file system;
- File systems infrastructure;
- JFS file system;
- Network file sys
OSV
linux-fips vulnerabilities
osv·2025-05-12·CVSS 7.8
CVE-2022-23041 [HIGH] linux-fips vulnerabilities
linux-fips vulnerabilities
Demi Marie Obenour and Simon Gaiser discovered that several Xen para-
virtualization device frontends did not properly restrict the access rights
of device backends. An attacker could possibly use a malicious Xen backend
to gain access to memory pages of a guest VM or cause a denial of service
in the guest. (CVE-2022-23041)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- GPU drivers;
- IIO subsystem;
- Media drivers;
- Network drivers;
- SCSI subsystem;
- SPI subsystem;
- USB Gadget drivers;
- Ceph distributed file system;
- File systems infrastructure;
- JFS file system;
- Network file system (N
OSV
linux-aws vulnerabilities
osv·2025-05-12·CVSS 7.8
CVE-2022-23041 [HIGH] linux-aws vulnerabilities
linux-aws vulnerabilities
Demi Marie Obenour and Simon Gaiser discovered that several Xen para-
virtualization device frontends did not properly restrict the access rights
of device backends. An attacker could possibly use a malicious Xen backend
to gain access to memory pages of a guest VM or cause a denial of service
in the guest. (CVE-2022-23041)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- GPU drivers;
- IIO subsystem;
- Media drivers;
- Network drivers;
- SCSI subsystem;
- SPI subsystem;
- USB Gadget drivers;
- Ceph distributed file system;
- File systems infrastructure;
- JFS file system;
- Network file system (NF
OSV
linux, linux-aws, linux-kvm vulnerabilities
osv·2025-05-12·CVSS 7.8
CVE-2022-23041 [HIGH] linux, linux-aws, linux-kvm vulnerabilities
linux, linux-aws, linux-kvm vulnerabilities
Demi Marie Obenour and Simon Gaiser discovered that several Xen para-
virtualization device frontends did not properly restrict the access rights
of device backends. An attacker could possibly use a malicious Xen backend
to gain access to memory pages of a guest VM or cause a denial of service
in the guest. (CVE-2022-23041)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- GPU drivers;
- IIO subsystem;
- Media drivers;
- Network drivers;
- SCSI subsystem;
- SPI subsystem;
- USB Gadget drivers;
- Ceph distributed file system;
- File systems infrastructure;
- JFS file system;
- Netwo
OSV
CVE-2021-47506: In the Linux kernel, the following vulnerability has been resolved: nfsd: fix use-after-free due to delegation race A delegation break could arrive as
osv·2024-05-24·CVSS 7.8
CVE-2021-47506 [HIGH] CVE-2021-47506: In the Linux kernel, the following vulnerability has been resolved: nfsd: fix use-after-free due to delegation race A delegation break could arrive as
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix use-after-free due to delegation race A delegation break could arrive as soon as we've called vfs_setlease. A delegation break runs a callback which immediately (in nfsd4_cb_recall_prepare) adds the delegation to del_recall_lru. If we then exit nfs4_set_delegation without hashing the delegation, it will be freed as soon as the callback is done with it, without ever being removed from del_recall_lru. Symptoms show up later as use-after-free or list corruption warnings, usually in the laundromat thread. I suspect aba2072f4523 "nfsd: grant read delegations to clients holding writes" made this bug easier to hit, but I looked as far back as v3.0 and it looks to me it already had the same problem. So I'm not sure where
No detection rules found.
No public exploits indexed.
https://git.kernel.org/stable/c/04a8d07f3d58308b92630045560799a3faa3ebcehttps://git.kernel.org/stable/c/148c816f10fd11df27ca6a9b3238cdd42fa72cd3https://git.kernel.org/stable/c/2becaa990b93cbd2928292c0b669d3abb6cf06d4https://git.kernel.org/stable/c/33645d3e22720cac1e4548f8fef57bf0649536eehttps://git.kernel.org/stable/c/348714018139c39533c55661a0c7c990671396b4https://git.kernel.org/stable/c/548ec0805c399c65ed66c6641be467f717833ab5https://git.kernel.org/stable/c/e0759696de6851d7536efddfdd2dfed4c4df1f09https://git.kernel.org/stable/c/eeb0711801f5e19ef654371b627682aed3b11373https://git.kernel.org/stable/c/04a8d07f3d58308b92630045560799a3faa3ebcehttps://git.kernel.org/stable/c/148c816f10fd11df27ca6a9b3238cdd42fa72cd3https://git.kernel.org/stable/c/2becaa990b93cbd2928292c0b669d3abb6cf06d4https://git.kernel.org/stable/c/33645d3e22720cac1e4548f8fef57bf0649536eehttps://git.kernel.org/stable/c/348714018139c39533c55661a0c7c990671396b4https://git.kernel.org/stable/c/548ec0805c399c65ed66c6641be467f717833ab5https://git.kernel.org/stable/c/e0759696de6851d7536efddfdd2dfed4c4df1f09https://git.kernel.org/stable/c/eeb0711801f5e19ef654371b627682aed3b11373
2024-05-24
Published