🛡️ CVE-2023-53240 on Ubuntu — linux
Description
In the Linux kernel, the following vulnerability has been resolved: xsk: check IFF_UP earlier in Tx path Xsk Tx can be triggered via either sendmsg() or poll() syscalls. These two paths share a call to common function xsk_xmit() which has two sanity checks within. A pseudo code example to show the two paths: __xsk_sendmsg() : xsk_poll(): if (unlikely(!xsk_is_bound(xs))) if (unlikely(!xsk_is_bound(xs))) return -ENXIO; return mask; if (unlikely(need_wait)) (...) return -EOPNOTSUPP; xsk_xmit() mark napi id (...) xsk_xmit() xsk_xmit(): if (unlikely(!(xs->dev->flags & IFF_UP))) return -ENETDOWN; if (unlikely(!xs->tx)) return -ENOBUFS; As it can be observed above, in sendmsg() napi id can be marked on interface that was not brought up and this causes a NULL ptr dereference: [31757.505631] BUG: kernel NULL pointer dereference, address: 0000000000000018 [31757.512710] #PF: supervisor read access in kernel mode [31757.517936] #PF: error_code(0x0000) - not-present page [31757.523149] PGD 0 P4D 0 [31757.525726] Oops: 0000 [#1] PREEMPT SMP NOPTI [31757.530154] CPU: 26 PID: 95641 Comm: xdpsock Not tainted 6.2.0-rc5+ #40 [31757.536871] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [31757.547457] RIP: 0010:xsk_sendmsg+0xde/0x180 [31757.551799] Code: 00 75 a2 48 8b 00 a8 04 75 9b 84 d2 74 69 8b 85 14 01 00 00 85 c0 75 1b 48 8b 85 28 03 00 00 48 8b 80 98 00 00 00 48 8b 40 20 <8b> 40 18 89 85 14 01 00 00 8b bd 14 01 00 00 81 ff 00 01 00 00 0f [31757.570840] RSP: 0018:ffffc90034f27dc0 EFLAGS: 00010246 [31757.576143] RAX: 0000000000000000 RBX: ffffc90034f27e18 RCX: 0000000000000000 [31757.583389] RDX: 0000000000000001 RSI: ffffc90034f27e18 RDI: ffff88984cf3c100 [31757.590631] RBP: ffff88984714a800 R08: ffff88984714a800 R09: 0000000000000000 [31757.597877] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffffa [31757.605123] R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000 [31757.612364] FS: 00007fb4c5931180(0000) GS:ffff88afdfa00000(0000) knlGS:0000000000000000 [31757.620571] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [31757.626406] CR2: 0000000000000018 CR3: 000000184b41c003 CR4: 00000000007706e0 [31757.633648] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [31757.640894] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [31757.648139] PKRU: 55555554 [31757.650894] Call Trace: [31757.653385] <TASK> [31757.655524] sock_sendmsg+0x8f/0xa0 [31757.659077] ? sockfd_lookup_light+0x12/0x70 [31757.663416] __sys_sendto+0xfc/0x170 [31757.667051] ? do_sched_setscheduler+0xdb/0x1b0 [31757.671658] __x64_sys_sendto+0x20/0x30 [31757.675557] do_syscall_64+0x38/0x90 [31757.679197] entry_SYSCALL_64_after_hwframe+0x72/0xdc [31757.687969] Code: 8e f6 ff 44 8b 4c 24 2c 4c 8b 44 24 20 41 89 c4 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 3a 44 89 e7 48 89 44 24 08 e8 b5 8e f6 ff 48 [31757.707007] RSP: 002b:00007ffd49c73c70 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [31757.714694] RAX: ffffffffffffffda RBX: 000055a996565380 RCX: 00007fb4c5727c16 [31757.721939] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [31757.729184] RBP: 0000000000000040 R08: 0000000000000000 R09: 0000000000000000 [31757.736429] R10: 0000000000000040 R11: 0000000000000293 R12: 0000000000000000 [31757.743673] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [31757.754940] </TASK> To fix this, let's make xsk_xmit a function that will be responsible for generic Tx, where RCU is handled accordingly and pull out sanity checks and xs->zc handling. Populate sanity checks to __xsk_sendmsg() and xsk_poll().
Distribution advisory
This page covers CVE-2023-53240 as tracked by Ubuntu, for the package linux. No fixed version has been recorded for this distribution yet.
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 none, integrity none, 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:N/I:N/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: None.
- Integrity impact: None.
- Availability impact: High — total loss, or loss the attacker controls.
Affected software
UBUNTU-CVE-2023-53240 is recorded against 111 packages.
- linux
- linux-allwinner-5.19
- linux-aws
- linux-aws-5.0
- linux-aws-5.11
- linux-aws-5.13
- linux-aws-5.15
- linux-aws-5.19
- linux-aws-5.3
- linux-aws-5.8
- linux-aws-6.2
- linux-aws-6.5
- linux-aws-fips
- linux-azure
- linux-azure-5.11
- linux-azure-5.13
- linux-azure-5.15
- linux-azure-5.19
- linux-azure-5.3
- linux-azure-5.8
- linux-azure-6.11
- linux-azure-6.2
- linux-azure-6.5
- linux-azure-edge
Show the remaining 87 packages
- linux-azure-fde
- linux-azure-fde-5.19
- linux-azure-fde-6.2
- linux-azure-fips
- linux-bluefield
- linux-fips
- linux-gcp
- linux-gcp-5.11
- linux-gcp-5.13
- linux-gcp-5.15
- linux-gcp-5.19
- linux-gcp-5.3
- linux-gcp-5.8
- linux-gcp-6.11
- linux-gcp-6.2
- linux-gcp-6.5
- linux-gcp-fips
- linux-gke
- linux-gke-4.15
- linux-gke-5.15
- linux-gke-5.4
- linux-gkeop
- linux-gkeop-5.15
- linux-gkeop-5.4
- linux-hwe
- linux-hwe-5.11
- linux-hwe-5.13
- linux-hwe-5.15
- linux-hwe-5.19
- linux-hwe-5.8
- linux-hwe-6.11
- linux-hwe-6.2
- linux-hwe-6.5
- linux-hwe-edge
- linux-ibm
- linux-ibm-5.15
- linux-intel
- linux-intel-5.13
- linux-intel-iot-realtime
- linux-intel-iotg
- linux-intel-iotg-5.15
- linux-kvm
- linux-lowlatency
- linux-lowlatency-hwe-5.15
- linux-lowlatency-hwe-5.19
- linux-lowlatency-hwe-6.11
- linux-lowlatency-hwe-6.2
- linux-lowlatency-hwe-6.5
- linux-nvidia
- linux-nvidia-6.2
- linux-nvidia-6.5
- linux-nvidia-tegra
- linux-nvidia-tegra-5.15
- linux-nvidia-tegra-igx
- linux-oem
- linux-oem-5.10
- linux-oem-5.13
- linux-oem-5.14
- linux-oem-5.17
- linux-oem-5.6
- linux-oem-6.0
- linux-oem-6.1
- linux-oem-6.11
- linux-oem-6.5
- linux-oem-6.8
- linux-oracle
- linux-oracle-5.0
- linux-oracle-5.11
- linux-oracle-5.13
- linux-oracle-5.15
- linux-oracle-5.3
- linux-oracle-5.8
- linux-oracle-6.5
- linux-raspi
- linux-raspi-realtime
- linux-raspi2
- linux-realtime
- linux-riscv
- linux-riscv-5.11
- linux-riscv-5.15
- linux-riscv-5.19
- linux-riscv-5.8
- linux-riscv-6.5
- linux-starfive-5.19
- linux-starfive-6.2
- linux-starfive-6.5
- linux-xilinx-zynqmp
Timeline and source
Published on 15 September 2025 and last revised on 18 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
www.cve.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
Other advisories for this package
linux has other advisories on record. If you are patching this one, these are worth checking on the same host:
- DEBIAN-CVE-2022-4994 (published 30 Jul 2026)
- CVE-2026-35233 (4.4 Medium, published 1 May 2026)
- CVE-2026-21996 (3.3 Low, published 1 May 2026)
- CVE-2026-21991 (5.5 Medium, published 16 Mar 2026)
- CGA-w6xv-3fg4-grm5 (published 29 Jan 2026)
- CGA-mcwh-q4vm-9f29 (published 29 Jan 2026)
- CGA-6xjj-65cr-mc7v (published 7 Jan 2026)
- CGA-m3jq-vcq5-mqrx (published 7 Jan 2026)
CVE-2023-53240 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| linux | — | — |
| linux-allwinner-5.19 | — | — |
| linux-aws | — | — |
| linux-aws-5.0 | — | — |
| linux-aws-5.11 | — | — |
| linux-aws-5.13 | — | — |
| linux-aws-5.15 | — | — |
| linux-aws-5.19 | — | — |
| linux-aws-5.3 | — | — |
| linux-aws-5.8 | — | — |
| linux-aws-6.2 | — | — |
| linux-aws-6.5 | — | — |
| linux-aws-fips | — | — |
| linux-azure | — | — |
| linux-azure-5.11 | — | — |
| linux-azure-5.13 | — | — |
| linux-azure-5.15 | — | — |
| linux-azure-5.19 | — | — |
| linux-azure-5.3 | — | — |
| linux-azure-5.8 | — | — |
| linux-azure-6.11 | — | — |
| linux-azure-6.2 | — | — |
| linux-azure-6.5 | — | — |
| linux-azure-edge | — | — |
| linux-azure-fde | — | — |
| linux-azure-fde-5.19 | — | — |
| linux-azure-fde-6.2 | — | — |
| linux-azure-fips | — | — |
| linux-bluefield | — | — |
| linux-fips | — | — |
| linux-gcp | — | — |
| linux-gcp-5.11 | — | — |
| linux-gcp-5.13 | — | — |
| linux-gcp-5.15 | — | — |
| linux-gcp-5.19 | — | — |
| linux-gcp-5.3 | — | — |
| linux-gcp-5.8 | — | — |
| linux-gcp-6.11 | — | — |
| linux-gcp-6.2 | — | — |
| linux-gcp-6.5 | — | — |
| linux-gcp-fips | — | — |
| linux-gke | — | — |
| linux-gke-4.15 | — | — |
| linux-gke-5.15 | — | — |
| linux-gke-5.4 | — | — |
| linux-gkeop | — | — |
| linux-gkeop-5.15 | — | — |
| linux-gkeop-5.4 | — | — |
| linux-hwe | — | — |
| linux-hwe-5.11 | — | — |
| linux-hwe-5.13 | — | — |
| linux-hwe-5.15 | — | — |
| linux-hwe-5.19 | — | — |
| linux-hwe-5.8 | — | — |
| linux-hwe-6.11 | — | — |
| linux-hwe-6.2 | — | — |
| linux-hwe-6.5 | — | — |
| linux-hwe-edge | — | — |
| linux-ibm | — | — |
| linux-ibm-5.15 | — | — |
| linux-intel | — | — |
| linux-intel-5.13 | — | — |
| linux-intel-iot-realtime | — | — |
| linux-intel-iotg | — | — |
| linux-intel-iotg-5.15 | — | — |
| linux-kvm | — | — |
| linux-lowlatency | — | — |
| linux-lowlatency-hwe-5.15 | — | — |
| linux-lowlatency-hwe-5.19 | — | — |
| linux-lowlatency-hwe-6.11 | — | — |
| linux-lowlatency-hwe-6.2 | — | — |
| linux-lowlatency-hwe-6.5 | — | — |
| linux-nvidia | — | — |
| linux-nvidia-6.2 | — | — |
| linux-nvidia-6.5 | — | — |
| linux-nvidia-tegra | — | — |
| linux-nvidia-tegra-5.15 | — | — |
| linux-nvidia-tegra-igx | — | — |
| linux-oem | — | — |
| linux-oem-5.10 | — | — |
| linux-oem-5.13 | — | — |
| linux-oem-5.14 | — | — |
| linux-oem-5.17 | — | — |
| linux-oem-5.6 | — | — |
| linux-oem-6.0 | — | — |
| linux-oem-6.1 | — | — |
| linux-oem-6.11 | — | — |
| linux-oem-6.5 | — | — |
| linux-oem-6.8 | — | — |
| linux-oracle | — | — |
| linux-oracle-5.0 | — | — |
| linux-oracle-5.11 | — | — |
| linux-oracle-5.13 | — | — |
| linux-oracle-5.15 | — | — |
| linux-oracle-5.3 | — | — |
| linux-oracle-5.8 | — | — |
| linux-oracle-6.5 | — | — |
| linux-raspi | — | — |
| linux-raspi-realtime | — | — |
| linux-raspi2 | — | — |
| linux-realtime | — | — |
| linux-riscv | — | — |
| linux-riscv-5.11 | — | — |
| linux-riscv-5.15 | — | — |
| linux-riscv-5.19 | — | — |
| linux-riscv-5.8 | — | — |
| linux-riscv-6.5 | — | — |
| linux-starfive-5.19 | — | — |
| linux-starfive-6.2 | — | — |
| linux-starfive-6.5 | — | — |
| linux-xilinx-zynqmp | — | — |
References
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