fs/overlayfs/copy_up.c in the Linux kernel before 4.2.6 uses an incorrect cleanup code path, which allows local users to cause a denial of service (dentry reference leak) via filesystem operations on a large file in a lower overlayfs layer.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-000640 advisory.

    fs/overlayfs/copy_up.c in the Linux kernel before 4.2.6 uses an incorrect cleanup code path, which allows     local users to cause a denial of service (dentry reference leak) via filesystem operations on a large file     in a lower overlayfs layer.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-002135 advisory.

    fs/overlayfs/copy_up.c in the Linux kernel before 4.2.6 uses an incorrect cleanup code path, which allows     local users to cause a denial of service (dentry reference leak) via filesystem operations on a large file     in a lower overlayfs layer.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-001828 advisory.

    fs/overlayfs/copy_up.c in the Linux kernel before 4.2.6 uses an incorrect cleanup code path, which allows     local users to cause a denial of service (dentry reference leak) via filesystem operations on a large file     in a lower overlayfs layer.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - fs/overlayfs/copy_up.c in the Linux kernel before 4.2.6 uses an incorrect cleanup code path, which allows     local users to cause a denial of service (dentry reference leak) via filesystem operations on a large file     in a lower overlayfs layer. (CVE-2015-8953)

Note that Nessus relies on the presence of the package as reported by the vendor.

According to the versions of the kernel packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities :

  - The snd_msndmidi_input_read function in     sound/isa/msnd/msnd_midi.c in the Linux kernel through     4.11.7 allows local users to cause a denial of service     (over-boundary access) or possibly have unspecified     other impact by changing the value of a message queue     head pointer between two kernel reads of that value,     aka a 'double fetch' vulnerability.(CVE-2017-9985i1/4%0

  - An assertion failure issue was found in the Linux     kernel's KVM hypervisor module built to support     visualization on ARM64 architecture platforms. The     failure could occur while accessing Performance     Monitors Cycle Count Register (PMCCNTR) from a guest. A     privileged guest user could use this flaw to crash the     host kernel resulting in denial of     service.(CVE-2017-12168i1/4%0

  - The iscsi_if_rx() function in     'drivers/scsi/scsi_transport_iscsi.c' in the Linux     kernel from v2.6.24-rc1 through 4.13.2 allows local     users to cause a denial of service (a system panic) by     making a number of certain syscalls by leveraging     incorrect length validation in the kernel     code.(CVE-2017-14489i1/4%0

  - The hdpvr_probe function in     drivers/media/usb/hdpvr/hdpvr-core.c in the Linux     kernel through 4.13.11 allows local users to cause a     denial of service (improper error handling and system     crash) or possibly have unspecified other impact via a     crafted USB device.(CVE-2017-16644i1/4%0

  - The dvb frontend management subsystem in the Linux     kernel contains a use-after-free which can allow a     malicious user to write to memory that may be assigned     to another kernel structure. This could create memory     corruption, panic, or possibly other side     affects.(CVE-2017-16648i1/4%0

  - It was found that the Linux kernel's IPv6     implementation mishandled socket options. A local     attacker could abuse concurrent access to the socket     options to escalate their privileges, or cause a denial     of service (use-after-free and system crash) via a     crafted sendmsg system call.(CVE-2016-3841i1/4%0

  - A flaw was found in the Linux kernel's ext4 filesystem.
    A local user can cause a use-after-free in     ext4_xattr_set_entry function and a denial of service     or unspecified other impact may occur by renaming a     file in a crafted ext4 filesystem     image.(CVE-2018-10879i1/4%0

  - A race condition was found in the Linux kernel, present     since v3.14-rc1 through v4.12. The race happens between     threads of inotify_handle_event() and vfs_rename()     while running the rename operation against the same     file. As a result of the race the next slab data or the     slab's free list pointer can be corrupted with     attacker-controlled data, which may lead to the     privilege escalation.(CVE-2017-7533i1/4%0

  - A privilege-escalation vulnerability was discovered in     the Linux kernel built with User Namespace     (CONFIG_USER_NS) support. The flaw occurred when the     ptrace() system call was used on a root-owned process     to enter a user namespace. A privileged namespace user     could exploit this flaw to potentially escalate their     privileges on the system, outside the original     namespace.(CVE-2015-8709i1/4%0

  - Use-after-free vulnerability in     drivers/net/ppp/ppp_generic.c in the Linux kernel     before 4.5.2 allows local users to cause a denial of     service (memory corruption and system crash, or     spinlock) or possibly have unspecified other impact by     removing a network namespace, related to the     ppp_register_net_channel and ppp_unregister_channel     functions.(CVE-2016-4805i1/4%0

  - A flaw was found in the way the Linux kernel's     kvm_iommu_map_pages() function handled IOMMU mapping     failures. A privileged user in a guest with an assigned     host device could use this flaw to crash the     host.(CVE-2014-3601i1/4%0

  - A flaw was found in the Linux kernel's implementation     of associative arrays introduced in 3.13. This     functionality was backported to the 3.10 kernels in Red     Hat Enterprise Linux 7. The flaw involved a null     pointer dereference in assoc_array_apply_edit() due to     incorrect node-splitting in assoc_array implementation.
    This affects the keyring key type and thus key addition     and link creation operations may cause the kernel to     panic.(CVE-2017-12193i1/4%0

  - Multiple race conditions in drivers/char/adsprpc.c and     drivers/char/adsprpc_compat.c in the ADSPRPC driver for     the Linux kernel 3.x, as used in Qualcomm Innovation     Center (QuIC) Android contributions for MSM devices and     other products, allow attackers to cause a denial of     service (zero-value write) or possibly have unspecified     other impact via a COMPAT_FASTRPC_IOCTL_INVOKE_FD ioctl     call.(CVE-2015-0572i1/4%0

  - The sanity_check_ckpt function in fs/f2fs/super.c in     the Linux kernel before version 4.12.4 does not     validate the blkoff and segno arrays. This allows an     unprivileged, local user to cause a system panic and     DoS. Due to the nature of the flaw, privilege     escalation cannot be fully ruled out, although we     believe it is unlikely.(CVE-2017-10663i1/4%0

  - A stack overflow flaw caused by infinite recursion was     found in the way the Linux kernel's Universal Disk     Format (UDF) file system implementation processed     indirect Information Control Blocks (ICBs). An attacker     with physical access to the system could use a     specially crafted UDF image to crash the     system.(CVE-2014-6410i1/4%0

  - Race condition in the ion_ioctl function in     drivers/staging/android/ion/ion.c in the Linux kernel     before 4.6 allows local users to gain privileges or     cause a denial of service (use-after-free) by calling     ION_IOC_FREE on two CPUs at the same     time.(CVE-2016-9120i1/4%0

  - drivers/hid/hid-picolcd_core.c in the Human Interface     Device (HID) subsystem in the Linux kernel through     3.11, when CONFIG_HID_PICOLCD is enabled, allows     physically proximate attackers to cause a denial of     service (NULL pointer dereference and OOPS) via a     crafted device.(CVE-2013-2899i1/4%0

  - A flaw was found in the Linux kernel's implementation     of overlayfs. An attacker can leak file resources in     the system by opening a large file with write     permissions on a overlay filesystem that is     insufficient to deal with the size of the write.When     unmounting the underlying device, the system is unable     to free an inode and this will consume resources.
    Repeating this for all available inodes and memory will     create a denial of service situation.(CVE-2015-8953i1/4%0

  - Buffer overflow in the mp_override_legacy_irq()     function in arch/x86/kernel/acpi/boot.c in the Linux     kernel through 4.12.2 allows local users to gain     privileges via a crafted ACPI table.(CVE-2017-11473i1/4%0

  - Use-after-free vulnerability in the     kvm_ioctl_create_device function in virt/kvm/kvm_main.c     in the Linux kernel before 4.8.13 allows host OS users     to cause a denial of service (host OS crash) or     possibly gain privileges via crafted ioctl calls on the     /dev/kvm device.(CVE-2016-10150i1/4%0

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the kernel packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

  - An information-leak vulnerability was found in the     kernel when it truncated a file to a smaller size which     consisted of an inline extent that was compressed. The     data between the new file size and the old file size     was not discarded and the number of bytes used by the     inode were not correctly decremented, which gave the     wrong report for callers of the stat(2) syscall. This     wasted metadata space and allowed for the truncated     data to be leaked, and data corruption or loss to     occur. A caller of the clone ioctl could exploit this     flaw by using only standard file-system operations     without root access to read the truncated     data.(CVE-2015-8374)

  - A flaw was found in the Linux kernel's key management     system where it was possible for an attacker to     escalate privileges or crash the machine. If a user key     gets negatively instantiated, an error code is cached     in the payload area. A negatively instantiated key may     be then be positively instantiated by updating it with     valid data. However, the -i1/4zupdate key type method     must be aware that the error code may be     there.(CVE-2015-8539)

  - A NULL pointer dereference flaw was found in the way     the Linux kernel's network subsystem handled socket     creation with an invalid protocol identifier. A local     user could use this flaw to crash the     system.(CVE-2015-8543)

  - An out-of-bounds flaw was found in the kernel, where     the length of the sockaddr parameter was not checked in     the pptp_bind() and pptp_connect() functions. As a     result, more kernel memory was copied out than     required, leaking information from the kernel stack     (including kernel addresses). A local system user could     exploit this flaw to bypass kernel ASLR or leak other     information.(CVE-2015-8569)

  - An out-of-bounds flaw was found in the kernel, where     the sco_sock_bind() function (bluetooth/sco) did not     check the length of its sockaddr parameter. As a     result, more kernel memory was copied out than     required, leaking information from the kernel stack     (including kernel addresses). A local user could     exploit this flaw to bypass kernel ASLR or leak other     information.(CVE-2015-8575)

  - The ovl_setattr function in fs/overlayfs/inode.c in the     Linux kernel through 4.3.3 attempts to merge distinct     setattr operations, which allows local users to bypass     intended access restrictions and modify the attributes     of arbitrary overlay files via a crafted     application.(CVE-2015-8660)

  - A NULL pointer dereference flaw was found in the Linux     kernel: the NFSv4.2 migration code improperly     initialized the kernel structure. A local,     authenticated user could use this flaw to cause a panic     of the NFS client (denial of service).(CVE-2015-8746)

  - A race condition flaw was found in the way the Linux     kernel's SCTP implementation handled sctp_accept()     during the processing of heartbeat timeout events. A     remote attacker could use this flaw to prevent further     connections to be accepted by the SCTP server running     on the system, resulting in a denial of     service.(CVE-2015-8767)

  - An infinite-loop flaw was found in the kernel. When a     local user calls the sys_writev syscall with a     specially crafted sequence of iov structs, the     fuse_fill_write_pages kernel function might never     terminate, instead continuing in a tight loop. This     process cannot be terminated and requires a     reboot.(CVE-2015-8785)

  - A NULL-pointer dereference vulnerability was found in     the Linux kernel's TCP stack, in     net/netfilter/nf_nat_redirect.c in the     nf_nat_redirect_ipv4() function. A remote,     unauthenticated user could exploit this flaw to create     a system crash (denial of service).(CVE-2015-8787)

  - A use-after-free flaw was found in the CXGB3 kernel     driver when the network was considered to be congested.
    The kernel incorrectly misinterpreted the congestion as     an error condition and incorrectly freed or cleaned up     the socket buffer (skb). When the device then sent the     skb's queued data, these structures were referenced. A     local attacker could use this flaw to panic the system     (denial of service) or, with a local account, escalate     their privileges.(CVE-2015-8812)

  - The hub_activate function in drivers/usb/core/hub.c in     the Linux kernel before 4.3.5 does not properly     maintain a hub-interface data structure, which allows     physically proximate attackers to cause a denial of     service (invalid memory access and system crash) or     possibly have unspecified other impact by unplugging a     USB hub device.(CVE-2015-8816)

  - The ioresources_init function in kernel/resource.c in     the Linux kernel through 4.7, as used in Android before     2016-08-05 on Nexus 6 and 7 (2013) devices, uses weak     permissions for /proc/iomem, which allows local users     to obtain sensitive information by reading this file,     aka Android internal bug 28814213 and Qualcomm internal     bug CR786116. NOTE: the permissions may be intentional     in most non-Android contexts.(CVE-2015-8944)

  - 'A flaw was found in the Linux kernel's implementation     of overlayfs. An attacker can leak file resources in     the system by opening a large file with write     permissions on a overlay filesystem that is     insufficient to deal with the size of the write.

  - When unmounting the underlying device, the system is     unable to free an inode and this will consume     resources. Repeating this for all available inodes and     memory will create a denial of service     situation.(CVE-2015-8953)'

  - The rfcomm_sock_bind function in     net/bluetooth/rfcomm/sock.c in the Linux kernel before     4.2 allows local users to obtain sensitive information     or cause a denial of service (NULL pointer dereference)     via vectors involving a bind system call on a Bluetooth     RFCOMM socket.(CVE-2015-8956)

  - A flaw was found in the ext4 subsystem. This     vulnerability is a use after free vulnerability was     found in __ext4_journal_stop(). Attackers could abuse     this to allow any code which attempts to deal with the     journal failure to be mishandled or not fail at all.
    This could lead to data corruption or     crashes.(CVE-2015-8961)

  - A flaw was found in the Linux kernel SCSI subsystem,     which allowed a local user to gain privileges or cause     a denial of service (memory corruption and system     crash) by issuing an SG_IO ioctl call while a device     was being detached.(CVE-2015-8962)

  - Race condition in kernel/events/core.c in the Linux     kernel before 4.4 allows local users to gain privileges     or cause a denial of service via use-after-free     vulnerability by leveraging incorrect handling of an     swevent data structure during a CPU unplug     operation.(CVE-2015-8963)

  - The tty_set_termios_ldisc() function in     'drivers/tty/tty_ldisc.c' in the Linux kernel before     4.5 allows local users to obtain sensitive information     from kernel memory by reading a tty data     structure.(CVE-2015-8964)

  - The lrw_crypt() function in 'crypto/lrw.c' in the Linux     kernel before 4.5 allows local users to cause a system     crash and a denial of service by the NULL pointer     dereference via accept(2) system call for AF_ALG socket     without calling setkey() first to set a cipher     key.(CVE-2015-8970)

  - It was found that kernel/events/core.c in the Linux     kernel mishandles counter grouping, which allows local     users to gain privileges via a crafted application,     related to the perf_pmu_register and perf_event_open     functions.(CVE-2015-9004)

  - A use-after-free flaw was discovered in the Linux     kernel's tty subsystem, which allows for the disclosure     of uncontrolled memory location and possible kernel     panic. The information leak is caused by a race     condition when attempting to set and read the tty line     discipline. A local attacker could use the TIOCSETD     (via tty_set_ldisc ) to switch to a new line discipline     a concurrent call to a TIOCGETD ioctl performing a read     on a given tty could then access previously allocated     memory. Up to 4 bytes could be leaked when querying the     line discipline or the kernel could panic with a     NULL-pointer dereference.(CVE-2016-0723)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
290470	Unity Linux 20.1050e / 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-000640)	Nessus	Unity Linux Local Security Checks	medium
287165	Unity Linux 20.1060a / 20.1070a Security Update: kernel (UTSA-2026-002135)	Nessus	Unity Linux Local Security Checks	medium
286670	Unity Linux 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-001828)	Nessus	Unity Linux Local Security Checks	medium
219197	Linux Distros Unpatched Vulnerability : CVE-2015-8953	Nessus	Misc.	medium
124976	EulerOS Virtualization for ARM 64 3.0.1.0 : kernel (EulerOS-SA-2019-1523)	Nessus	Huawei Local Security Checks	critical
124813	EulerOS Virtualization 3.0.1.0 : kernel (EulerOS-SA-2019-1489)	Nessus	Huawei Local Security Checks	critical

Detections

Analytics

CVE-2015-8953

medium

Tenable Plugins

medium

medium

medium

medium

critical

critical