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🛡️ CVE-2023-53354 — kernel

🟠 CVSS 7.8 — High ✅ No Known Exploit NVD
7.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

skbuff: skb_segment, Call zero copy functions before using skbuff frags

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.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Affected software

CVE-2023-53354 is recorded against 2 packages.

  • kernel (from 6.5.0 up to 6.5.3)
  • linux-kernel (from 6.5 up to 6.5.3)

Timeline and source

Published on 17 September 2025 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

Other advisories for this package

kernel has other advisories on record. If you are patching this one, these are worth checking on the same host:

CVE-2023-53354 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity High
CVSS Score 7.8
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2025-09-17
Updated 2026-08-20
Modified 2026-08-12

Affected Packages

Software From version Fixed in
kernel 6.5.0 6.5.3
linux-kernel 6.5 6.5.3

References

Similar Threats

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