Linux Kernel up to 6.1.23/6.2.10 ping /proc/net/icmp hlist_nulls null pointer dereference

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.1.23/6.2.10. This impacts the function hlist_nulls of the file /proc/net/icmp of the component ping. Performing a manipulation results in null pointer dereference. This vulnerability is cataloged as CVE-2023-53987. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.23/6.2.10. It has been classified as critical. This affects the function hlist_nulls of the file /proc/net/icmp of the component ping. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ping: Fix potentail NULL deref for /proc/net/icmp. After commit dbca1596bbb0 ("ping: convert to RCU lookups, get rid of rwlock"), we use RCU for ping sockets, but we should use spinlock for /proc/net/icmp to avoid a potential NULL deref mentioned in the previous patch. Let's go back to using spinlock there. Note we can convert ping sockets to use hlist instead of hlist_nulls because we do not use SLAB_TYPESAFE_BY_RCU for ping sockets.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2023-53987 since 12/24/2025. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 279977 (Linux Distros Unpatched Vulnerability : CVE-2023-53987), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.24 or 6.2.11 eliminates this vulnerability. Applying the patch 5a08a32e624908890aa0a2eb442bb6a7669891a8/176cbb6da28f36506cc60a4bec4ab8df0c16713a/ab5fb73ffa01072b4d8031cc05801fa1cb653bee is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (279977) and CERT Bund (WID-SEC-2025-2920). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.1.23
• 6.2.0
• 6.2.1
• 6.2.2
• 6.2.3
• 6.2.4
• 6.2.5
• 6.2.6
• 6.2.7
• 6.2.8
• 6.2.9
• 6.2.10

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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