SB2026081468 - openEuler 20.03 LTS SP4 update for kernel
Published: August 14, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 8 vulnerabilities.
1) Improper input validation (CVE-ID: CVE-2026-53392)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper input validation in ff_layout_alloc_lseg() in the NFSv4 flexfiles layout handling when processing a malformed flexfiles layout body with a zero filehandle-version array count. A remote attacker can send a specially crafted flexfiles layout to cause a denial of service.
The issue can lead to a null pointer dereference and kernel panic.
2) Use-after-free (CVE-ID: CVE-2026-53399)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a use-after-free in the nfsd layout stateid handling in fs/nfsd/nfs4layouts.c when processing layout stateid allocation failures after a setlease error. A remote user can trigger a setlease failure and subsequent IDR walker access to dereference a dangling pointer to cause a denial of service.
The issue occurs because a published stateid remains referenced in the IDR after the associated memory is freed, and a related destructor path may access uninitialized delayed work on the same failure path.
3) Out-of-bounds read (CVE-ID: CVE-2026-64191)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to out-of-bounds read and out-of-bounds write in stub_xfer() in the i2c-stub driver when handling an I2C_SMBUS ioctl with I2C_SMBUS_I2C_BLOCK_DATA and an invalid block length. A local user can issue a crafted ioctl request with data->block[0] greater than 32 to cause a denial of service.
The issue affects the development and test i2c-stub driver, which is not built by default and must be loaded with a chip_addr= parameter.
4) Use-after-free (CVE-ID: CVE-2026-64266)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in fuse_ref_folio() in the FUSE subsystem when handling a subsequent copy chain after unlocking the request. A local user can trigger request abort and asynchronous end callback timing to cause a denial of service.
5) Out-of-bounds read (CVE-ID: CVE-2026-64299)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in regex_match_glob() glob matching in the tracing event filter subsystem when processing non-NUL-terminated string event fields. A local user can supply a crafted glob filter against such fields to disclose sensitive information.
One reported path reaches the issue from the xfs_lookup tracepoint, and the affected string fields may be dynamic char arrays copied without a trailing NUL byte.
6) Deadlock (CVE-ID: CVE-2026-64374)
CWE-ID: CWE-833 - Deadlock
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a live lock condition in the linux kernel scheduler RT_PUSH_IPI logic when handling RT task migration and repeated inter-processor interrupts on non-PREEMPT_RT systems. A local user can trigger heavy networking activity and wake RT tasks to cause a denial of service.
The issue occurs on non-PREEMPT_RT systems when softirqs execute for long periods and prevent the target CPU from returning to task context.
7) Improper access control (CVE-ID: CVE-2026-64388)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to bypass ownership and group changes.
The vulnerability exists due to improper access control in cifs_setattr_nounix() when processing chown and chgrp operations on mounts using SMB3 POSIX Extensions. A local user can change file ownership or group attributes in a way that is ignored to bypass ownership and group changes.
The issue occurs only when SMB3 POSIX Extensions are used without the relevant ACL or SID-based mount options enabled.
8) Out-of-bounds read (CVE-ID: CVE-2026-64456)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in the virtio-rng driver copy_data() function when processing device-reported used.len values from a virtio-rng backend. A remote attacker can provide a specially crafted length value to disclose sensitive information.
The issue can leak adjacent guest-kernel slab contents through the guest RNG and can also be observed directly via /dev/hwrng. No guest userspace interaction is required for the initial out-of-bounds read to occur.
Remediation
Install update from vendor's website.