CVE-2024-38596 — af_unix: Fix data races in unix_release_sock/unix_stream_sendmsg
In the Linux kernel, the following vulnerability has been resolved: af_unix: Fix data races in unix_release_sock/unix_stream_sendmsg A data-race condition has been identified in af_unix. In one data path, the write function unix_release_sock() atomically writes to sk->sk_shutdown using WRITE_ONCE. However, on the reader side, unix_stream_sendmsg() does not read it atomically. Consequently, this issue is causing the following KCSAN splat to occur: BUG: KCSAN: data-race in unix_release_sock / unix_stream_sendmsg write (marked) to 0xffff88867256ddbb of 1 bytes by task 7270 on cpu 28: unix_release_sock (net/unix/af_unix.c:640) unix_release (net/unix/af_unix.c:1050) sock_close (net/socket.c:659 net/socket.c:1421) __fput (fs/file_table.c:422) __fput_sync (fs/file_table.c:508) __se_sys_close (fs/open.c:1559 fs/open.c:1541) __x64_sys_close (fs/open.c:1541) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) read to 0xffff88867256ddbb of 1 bytes by task 989 on cpu 14: unix_stream_sendmsg (net/unix/af_unix.c:2273) __sock_sendmsg (net/socket.c:730 net/socket.c:745) ____sys_sendmsg (net/socket.c:2584) __sys_sendmmsg (net/socket.c:2638 net/socket.c:2724) __x64_sys_sendmmsg (net/socket.c:2753 net/socket.c:2750 net/socket.c:2750) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) value changed: 0x01 -> 0x03 The line numbers are related to commit dd5a440a31fa ("Linux 6.9-rc7"). Commit e1d09c2c2f57 ("af_unix: Fix data races around sk->sk_shutdown.") addressed a comparable issue in the past regarding sk->sk_shutdown. However, it overlooked resolving this particular data path. This patch only offending unix_stream_sendmsg() function, since the other reads seem to be protected by unix_state_lock() as discussed in
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (logic error), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
version 2.6.12≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 540bf24fba16b88c1b3b9353927204b4f1074e25≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < a52fa2addfcccc2c5a0217fd45562605088c018b≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < a4c88072abcaca593cefe70f90e9d3707526e8f9≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 0688d4e499bee3f2749bca27329bd128686230cb≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 8299e4d778f664b31b67cf4cf3d5409de2ecb92c≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 9aa8773abfa0e954136875b4cbf2df4cf638e8a5≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 4d51845d734a4c5d079e56e0916f936a55e15055 and 2 more≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < de6641d213373fbde9bbdd7c4b552254bc9f82fe≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < fca6072e1a7b1e709ada5604b951513b89b4bd0a |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 2.6.12-rc4version 2.6.12-rc5≥ 2.6.13 and < 4.19.316version 2.6.12-rc3version 2.6.12-rc2version 2.6.12≥ 6.9 and < 6.9.3≥ 6.7 and < 6.8.12 and 5 more≥ 6.2 and < 6.6.33≥ 5.16 and < 6.1.93≥ 5.11 and < 5.15.161≥ 5.5 and < 5.10.219≥ 4.20 and < 5.4.278 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 4.7 | CVSS 3.1 | Medium | 1.0 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 4.7 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · linux/linux kernel
- CVSS changed · 4.7
- Source status changed · → Modified
- Record created in this database
- 2024
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
15 on the record
- git.kernel.org/stable/c/0688d4e499bee3f2749bca27329bd128686230cb
- git.kernel.org/stable/c/4d51845d734a4c5d079e56e0916f936a55e15055
- git.kernel.org/stable/c/a4c88072abcaca593cefe70f90e9d3707526e8f9
- git.kernel.org/stable/c/fca6072e1a7b1e709ada5604b951513b89b4bd0a
- git.kernel.org/stable/c/de6641d213373fbde9bbdd7c4b552254bc9f82fe
- git.kernel.org/stable/c/540bf24fba16b88c1b3b9353927204b4f1074e25
- git.kernel.org/stable/c/8299e4d778f664b31b67cf4cf3d5409de2ecb92c
- git.kernel.org/stable/c/a52fa2addfcccc2c5a0217fd45562605088c018b
- git.kernel.org/stable/c/9aa8773abfa0e954136875b4cbf2df4cf638e8a5
- nvd.nist.gov/vuln/detail/CVE-2024-38596
- cert-portal.siemens.com/productcert/html/ssa-398330.html
- github.com/advisories/GHSA-7fm3-3cqw-x6wj
- cert-portal.siemens.com/productcert/html/ssa-613116.html
- lists.debian.org/debian-lts-announce/2024/06/msg00020.html
- cert-portal.siemens.com/productcert/html/ssa-265688.html
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 6h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 6h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2024-38596 is "af_unix: Fix data races in unix_release_sock/unix_stream_sendmsg", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.7 describes technical severity. EPSS 0.19% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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