CVE-2026-64396
published 2026-07-25CVE-2026-64396: In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation When a blocking…
PriorityP351high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
EPSS
0.63%
48.7th percentile
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation
When a blocking byte-range lock request is deferred in the
FILE_LOCK_DEFERRED path, ksmbd registers the asynchronous work into
the connection's async_requests list via setup_async_work(). The cancel
callback smb2_remove_blocked_lock() holds a reference to the flock.
If the lock waiter is subsequently woken up but the work state is no
longer KSMBD_WORK_ACTIVE (e.g., due to a concurrent cancellation), the
cleanup path calls locks_free_lock(flock) without dequeuing the work from
the async_requests list. Concurrently, smb2_cancel() walks the list
under conn->request_lock and invokes the cancel callback, which then
dereferences the already freed 'flock'. This leads to a slab-use-after-free
inside __wake_up_common.
Fix this by restructuring the cleanup logic after the worker returns
from ksmbd_vfs_posix_lock_wait(). Move list_del(&smb_lock->llist) and
release_async_work(work) to the top of the cleanup block. This guarantees
that the async work is completely dequeued and serialized under
conn->request_lock before locks_free_lock(flock) is called, rendering
the flock unreachable for any concurrent smb2_cancel().
Affected
30 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 367c42a611fe488b7b03f1f6737f4dee0e8b20a2 | 367c42a611fe488b7b03f1f6737f4dee0e8b20a2 |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 7703fd9aba1f2483c8e55f9ff73b7663e0761ed9 | 7703fd9aba1f2483c8e55f9ff73b7663e0761ed9 |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 463bbd79698513af4dad50fe1c573825f297ca2e | 463bbd79698513af4dad50fe1c573825f297ca2e |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 5aa1cb01155f96824003baf7997cdf1f150caba3 | 5aa1cb01155f96824003baf7997cdf1f150caba3 |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 5c75275c0fc9a2deb0d8f5604edcb16f288171c8 | 5c75275c0fc9a2deb0d8f5604edcb16f288171c8 |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < d20d1c8ba5765d1d12eefc0aee6385ab3f240e1e | d20d1c8ba5765d1d12eefc0aee6385ab3f240e1e |
| linux | linux_kernel | >= 5.15 < 6.1.178 | 6.1.178 |
| linux | linux_kernel | >= 6.13 < 6.18.39 | 6.18.39 |
| linux | linux_kernel | >= 6.19 < 7.1.4 | 7.1.4 |
| linux | linux_kernel | >= 6.2 < 6.6.145 | 6.6.145 |
| linux | linux_kernel | >= 6.7 < 6.12.96 | 6.12.96 |
| ubuntu | linux | — | — |
| ubuntu | linux-aws | — | — |
| ubuntu | linux-aws-7.0 | — | — |
| ubuntu | linux-azure | — | — |
| ubuntu | linux-azure-7.0 | — | — |
| ubuntu | linux-gcp | — | — |
| ubuntu | linux-gcp-7.0 | — | — |
| ubuntu | linux-gke | — | — |
| ubuntu | linux-hwe-7.0 | — | — |
| ubuntu | linux-ibm | — | — |
| ubuntu | linux-nvidia-7.0 | — | — |
| ubuntu | linux-nvidia-bos | — | — |
| ubuntu | linux-nvidia-tegra | — | — |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vendor_ubuntu9.1CRITICAL
vendor_redhat8.8HIGH
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Ubuntu
Linux kernel (Oracle) vulnerabilities
vendor_ubuntu·2026-09-29·CVSS 9.1
CVE-2026-64191 [CRITICAL] Linux kernel (Oracle) vulnerabilities
Title: Linux kernel (Oracle) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were d
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-09-22·CVSS 9.1
CVE-2026-63869 [CRITICAL] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390 architecture;
Ubuntu
Linux kernel (Azure) vulnerabilities
vendor_ubuntu·2026-09-22·CVSS 9.1
CVE-2026-52938 [CRITICAL] Linux kernel (Azure) vulnerabilities
Title: Linux kernel (Azure) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were di
Ubuntu
Linux kernel (NVIDIA BaseOS) vulnerabilities
vendor_ubuntu·2026-09-22
CVE-2026-64504 Linux kernel (NVIDIA BaseOS) vulnerabilities
Title: Linux kernel (NVIDIA BaseOS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
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:
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- ARM64 architecture;
- RISC-V architecture;
- S390 architecture;
- x86 architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- Intel NPU Driver;
- ACPI drivers;
- Android drivers;
- Drivers core;
- Compressed RAM block device driver;
- Bluetooth drivers;
- Character device driver;
- Hardware random number generator core;
- CPU frequency scaling framework;
- Hardware crypto device drivers
Ubuntu
Linux kernel (IBM) vulnerabilities
vendor_ubuntu·2026-09-21·CVSS 9.1
CVE-2026-63869 [CRITICAL] Linux kernel (IBM) vulnerabilities
Title: Linux kernel (IBM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390 architec
Ubuntu
Linux kernel (NVIDIA Tegra) vulnerabilities
vendor_ubuntu·2026-09-18·CVSS 9.1
CVE-2026-53358 [CRITICAL] Linux kernel (NVIDIA Tegra) vulnerabilities
Title: Linux kernel (NVIDIA Tegra) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- PowerPC architecture;
- RIS
Ubuntu
Linux kernel (Raspberry Pi) vulnerabilities
vendor_ubuntu·2026-09-18·CVSS 9.1
CVE-2026-64504 [CRITICAL] Linux kernel (Raspberry Pi) vulnerabilities
Title: Linux kernel (Raspberry Pi) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390
Ubuntu
Linux kernel (NVIDIA) vulnerabilities
vendor_ubuntu·2026-09-15
CVE-2026-63869 Linux kernel (NVIDIA) vulnerabilities
Title: Linux kernel (NVIDIA) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
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:
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- ARM64 architecture;
- RISC-V architecture;
- S390 architecture;
- x86 architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- Intel NPU Driver;
- ACPI drivers;
- Android drivers;
- Drivers core;
- Compressed RAM block device driver;
- Bluetooth drivers;
- Character device driver;
- Hardware random number generator core;
- CPU frequency scaling framework;
- Hardware crypto device drivers;
- Buf
Ubuntu
Linux kernel (GCP) vulnerabilities
vendor_ubuntu·2026-09-07·CVSS 9.1
CVE-2026-52938 [CRITICAL] Linux kernel (GCP) vulnerabilities
Title: Linux kernel (GCP) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were disc
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-09-07·CVSS 9.1
CVE-2026-64504 [CRITICAL] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390 architecture;
Ubuntu
Linux kernel (OEM) vulnerabilities
vendor_ubuntu·2026-09-07·CVSS 9.1
CVE-2026-63869 [CRITICAL] Linux kernel (OEM) vulnerabilities
Title: Linux kernel (OEM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
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:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390 architec
Red Hat
kernel: ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation
vendor_redhat·2026-07-25·CVSS 8.8
CVE-2026-64396 [HIGH] CWE-825 kernel: ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation
kernel: ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation
No description is available for this CVE.
Package: erlang27 (Red Hat Hardened Images) - Not affected
VulDB
Linux Kernel up to 7.1.3 ksmbd request_lock/llist use after free
vuldb·2026-09-05·CVSS 8.8
CVE-2026-64396 [HIGH] Linux Kernel up to 7.1.3 ksmbd request_lock/llist use after free
A vulnerability classified as very critical was found in Linux Kernel up to 6.1.177/6.6.144/6.12.95/6.18.38/7.1.3. Affected by this issue is the function smb2_remove_blocked_lock/ksmbd_vfs_posix_lock_wait of the component ksmbd. The manipulation of the argument request_lock/llist results in use after free.
This vulnerability was named CVE-2026-64396. The attack may be performed from remote. There is no available exploit.
Upgrading the affected component is advised.
GHSA
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in
ghsa_unreviewed·2026-07-25
CVE-2026-64396 In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation
When a blocking byte-range lock request is deferred in the
FILE_LOCK_DEFERRED path, ksmbd registers the asynchronous work into
the connection's async_requests list via setup_async_work(). The cancel
callback smb2_remove_blocked_lock() holds a reference to the flock.
If the lock waiter is subsequently woken up but the work state is no
longer KSMBD_WORK_ACTIVE (e.g., due to a concurrent cancellation), the
cleanup path calls locks_free_lock(flock) without dequeuing the work from
the async_requests list. Concurrently, smb2_cancel() walks the list
under conn->request_lock and invokes the cancel callback, which then
dereferences the already freed 'floc
No detection rules found.
No public exploits indexed.
https://git.kernel.org/stable/c/367c42a611fe488b7b03f1f6737f4dee0e8b20a2https://git.kernel.org/stable/c/463bbd79698513af4dad50fe1c573825f297ca2ehttps://git.kernel.org/stable/c/5aa1cb01155f96824003baf7997cdf1f150caba3https://git.kernel.org/stable/c/5c75275c0fc9a2deb0d8f5604edcb16f288171c8https://git.kernel.org/stable/c/7703fd9aba1f2483c8e55f9ff73b7663e0761ed9https://git.kernel.org/stable/c/d20d1c8ba5765d1d12eefc0aee6385ab3f240e1e
2026-07-25
Published