Cloudanix VulnDB

CVE-2023-54218

None

CVSS

—

EPSS

0.2%

Published

Dec 30, 2025

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A Linux kernel timing flaw in network data handling can produce unreliable results when many connections are active at once.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Other
Component
OS kernel
Class
Race Condition
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Data race allowing load-tearing on sk->sk_stamp read without READ_ONCE() in sock_recv_cmsgs(), enabling concurrent inconsistent 8-byte timestamp values during packet reception.

Why it matters to the business

Potential kernel instability or incorrect network timestamp handling under concurrent load, increasing risk of subtle failures in high-throughput networking environments; low immediate urgency given absent exploitation and low EPSS.

How an attack unfolds

No known end-to-end exploitation path exists; the race was identified via KCSAN fuzzing rather than attacker-controlled concurrent socket operations.

How to fix it

Upgrade Linux kernel to incorporate commit fd28692fa182d25e8d26bc1db506648839fde245 (or equivalent stable backports) which adds the required READ_ONCE() on sk_stamp.

How to confirm the fix worked

Confirm the READ_ONCE() macro wraps the sk_stamp load inside sock_recv_cmsgs() in include/net/sock.h and re-run KCSAN on packet_recvmsg paths to verify race elimination.

How to detect it

Search kernel logs and KCSAN reports for data-race warnings involving packet_recvmsg, sock_recv_cmsgs, and sk_stamp accesses.

What your security team should do

  • Apply the referenced kernel commit or newer stable release across all affected systems
  • Include KCSAN concurrency testing in kernel validation pipelines
  • Track upstream stable releases for additional related fixes

The record

In the Linux kernel, the following vulnerability has been resolved: net: Fix load-tearing on sk->sk_stamp in sock_recv_cmsgs(). KCSAN found a data race in sock_recv_cmsgs() where the read access to sk->sk_stamp needs READ_ONCE(). BUG: KCSAN: data-race in packet_recvmsg / packet_recvmsg write (marked) to 0xffff88803c81f258 of 8 bytes by task 19171 on cpu 0: sock_write_timestamp include/net/sock.h:2670 [inline] sock_recv_cmsgs include/net/sock.h:2722 [inline] packet_recvmsg+0xb97/0xd00 net/packet/af_packet.c:3489 sock_recvmsg_nosec net/socket.c:1019 [inline] sock_recvmsg+0x11a/0x130 net/socket.c:1040 sock_read_iter+0x176/0x220 net/socket.c:1118 call_read_iter include/linux/fs.h:1845 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x5e0/0x630 fs/read_write.c:470 ksys_read+0x163/0x1a0 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __x64_sys_read+0x41/0x50 fs/read_write.c:621 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffff88803c81f258 of 8 bytes by task 19183 on cpu 1: sock_recv_cmsgs include/net/sock.h:2721 [inline] packet_recvmsg+0xb64/0xd00 net/packet/af_packet.c:3489 sock_recvmsg_nosec net/socket.c:1019 [inline] sock_recvmsg+0x11a/0x130 net/socket.c:1040 sock_read_iter+0x176/0x220 net/socket.c:1118 call_read_iter include/linux/fs.h:1845 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x5e0/0x630 fs/read_write.c:470 ksys_read+0x163/0x1a0 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __x64_sys_read+0x41/0x50 fs/read_write.c:621 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0xffffffffc4653600 -> 0x0000000000000000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 19183 Comm: syz-executor.5 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Affected packages

Ecosystem Package Introduced Fixed
Linux Kernel 4.12.0 4.14.316

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