Linux Kernel up to 6.5.2 skb_segment null pointer dereference

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5.0$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.5.2. This issue affects the function skb_segment. The manipulation leads to null pointer dereference. This vulnerability is listed as CVE-2023-53354. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.5.2. This issue affects the function skb_segment. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to 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. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: skbuff: skb_segment, Call zero copy functions before using skbuff frags Commit bf5c25d60861 ("skbuff: in skb_segment, call zerocopy functions once per nskb") added the call to zero copy functions in skb_segment(). The change introduced a bug in skb_segment() because skb_orphan_frags() may possibly change the number of fragments or allocate new fragments altogether leaving nrfrags and frag to point to the old values. This can cause a panic with stacktrace like the one below. [ 193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc [ 193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G O 5.15.123+ #26 [ 193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0 [ 194.021892] Call Trace: [ 194.027422] <TASK> [ 194.072861] tcp_gso_segment+0x107/0x540 [ 194.082031] inet_gso_segment+0x15c/0x3d0 [ 194.090783] skb_mac_gso_segment+0x9f/0x110 [ 194.095016] __skb_gso_segment+0xc1/0x190 [ 194.103131] netem_enqueue+0x290/0xb10 [sch_netem] [ 194.107071] dev_qdisc_enqueue+0x16/0x70 [ 194.110884] __dev_queue_xmit+0x63b/0xb30 [ 194.121670] bond_start_xmit+0x159/0x380 [bonding] [ 194.128506] dev_hard_start_xmit+0xc3/0x1e0 [ 194.131787] __dev_queue_xmit+0x8a0/0xb30 [ 194.138225] macvlan_start_xmit+0x4f/0x100 [macvlan] [ 194.141477] dev_hard_start_xmit+0xc3/0x1e0 [ 194.144622] sch_direct_xmit+0xe3/0x280 [ 194.147748] __dev_queue_xmit+0x54a/0xb30 [ 194.154131] tap_get_user+0x2a8/0x9c0 [tap] [ 194.157358] tap_sendmsg+0x52/0x8e0 [tap] [ 194.167049] handle_tx_zerocopy+0x14e/0x4c0 [vhost_net] [ 194.173631] handle_tx+0xcd/0xe0 [vhost_net] [ 194.176959] vhost_worker+0x76/0xb0 [vhost] [ 194.183667] kthread+0x118/0x140 [ 194.190358] ret_from_fork+0x1f/0x30 [ 194.193670] </TASK> In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags local variable in skb_segment() stale. This resulted in the code hitting i >= nrfrags prematurely and trying to move to next frag_skb using list_skb pointer, which was NULL, and caused kernel panic. Move the call to zero copy functions before using frags and nr_frags.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2023-53354 since 09/16/2025. The exploitation is known to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 265644 (Linux Distros Unpatched Vulnerability : CVE-2023-53354), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.19.295, 5.4.257, 5.10.195, 5.15.132, 6.1.53, 6.4.16 or 6.5.3 eliminates this vulnerability. Applying the patch fcab3f661dbfd88e27ddbbe65368f3fa2d823175/d44403ec0676317b7f7edf2a035bb219fee3304e/8836c266201c29a5acb4f582227686f47b65ad61/d5790386595d06ea9decfd9ba5f1ea48cf09aa02/04c3eee4e13f60bf6f9a366ad39f88a01a57166e/f99006e840a4dbc8f5a34cecc6b5b26c73ef49bb/6c26ed3c6abe86ddab0510529000b970b05c9b40/2ea35288c83b3d501a88bc17f2df8f176b5cc96f 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 (265644) and CERT Bund (WID-SEC-2025-2087). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • SUSE Linux
  • Oracle Linux
  • IBM QRadar SIEM
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Dell Secure Connect Gateway

Productinfo

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Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 5.0

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 265644
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2023-53354

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 4.19.295/5.4.257/5.10.195/5.15.132/6.1.53/6.4.16/6.5.3
Patch: fcab3f661dbfd88e27ddbbe65368f3fa2d823175/d44403ec0676317b7f7edf2a035bb219fee3304e/8836c266201c29a5acb4f582227686f47b65ad61/d5790386595d06ea9decfd9ba5f1ea48cf09aa02/04c3eee4e13f60bf6f9a366ad39f88a01a57166e/f99006e840a4dbc8f5a34cecc6b5b26c73ef49bb/6c26ed3c6abe86ddab0510529000b970b05c9b40/2ea35288c83b3d501a88bc17f2df8f176b5cc96f

Timelineinfo

09/16/2025 CVE reserved
09/17/2025 +1 days Advisory disclosed
09/17/2025 +0 days VulDB entry created
12/27/2025 +101 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2023-53354 (🔒)
GCVE (CVE): GCVE-0-2023-53354
GCVE (VulDB): GCVE-100-324713
CERT Bund: WID-SEC-2025-2087 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 09/17/2025 17:45
Updated: 12/27/2025 04:13
Changes: 09/17/2025 17:45 (58), 09/21/2025 17:15 (2), 12/11/2025 18:20 (12), 12/27/2025 04:13 (7)
Complete: 🔍
Cache ID: 216::103

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

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