CVE-2026-53331 — slimbus: qcom-ngd-ctrl: Avoid ABBA on tx_lock/ctrl->lock
In the Linux kernel, the following vulnerability has been resolved: slimbus: qcom-ngd-ctrl: Avoid ABBA on tx_lock/ctrl->lock During the SSR/PDR down notification the tx_lock is taken with the intent to provide synchronization with active DMA transfers. But during this period qcom_slim_ngd_down() is invoked, which ends up in slim_report_absent(), which takes the slim_controller lock. In multiple other codepaths these two locks are taken in the opposite order (i.e. slim_controller then tx_lock). The result is a lockdep splat, and a possible deadlock: rprocctl/449 is trying to acquire lock: ffff00009793e620 (&ctrl->lock){+.+.}-{4:4}, at: slim_report_absent (drivers/slimbus/core.c:322) slimbus but task is already holding lock: ffff00009793fb50 (&ctrl->tx_lock){+.+.}-{4:4}, at: qcom_slim_ngd_ssr_pdr_notify (drivers/slimbus/qcom-ngd-ctrl.c:1475) slim_qcom_ngd_ctrl which lock already depends on the new lock. Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ctrl->tx_lock); lock(&ctrl->lock); lock(&ctrl->tx_lock); lock(&ctrl->lock); The assumption is that the comment refers to the desire to not call qcom_slim_ngd_exit_dma() while we have an ongoing DMA TX transaction. But any such transaction is initiated and completed within a single qcom_slim_ngd_xfer_msg(). Prior to calling qcom_slim_ngd_exit_dma() the slim_controller is torn down, all child devices are notified that the slimbus is gone and the child devices are removed. Stop taking the tx_lock in qcom_slim_ngd_ssr_pdr_notify() to avoid the deadlock.
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 0.1% (30-day exploitation probability)+0
- 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.
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)
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, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | version 5.11≥ a899d324863a3d15ce0eea513884e1b73a758c58 and < 55f2ea9ff83cc27a85526b14bc9b32f96a08d6ec≥ a899d324863a3d15ce0eea513884e1b73a758c58 and < 9708eb50fd7343145b422be852f890212155d845≥ a899d324863a3d15ce0eea513884e1b73a758c58 and < 9f0d45d509b434c54da10e01f4ef8086e4583401≥ a899d324863a3d15ce0eea513884e1b73a758c58 and < aad4337a21b9ad3ae8d668fa8678d05e26ecbaa8≥ a899d324863a3d15ce0eea513884e1b73a758c58 and < d54a221b0f3cd9e1f03f18104be34e02a8258fae≥ a899d324863a3d15ce0eea513884e1b73a758c58 and < dc4d5c57e012c2c669793deb1515a57bbc6bf5dd≥ a899d324863a3d15ce0eea513884e1b73a758c58 and < 3d1561537237c6cc1db76155183d8bbdac2339f0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 7.1-rc5version 7.1-rc7version 7.1-rc6≥ 5.11 and < 5.15.210version 7.1-rc4version 7.1-rc3version 7.1-rc2version 7.1-rc1 and 5 more≥ 6.19 and < 7.0.13≥ 6.13 and < 6.18.36≥ 6.7 and < 6.12.94≥ 6.2 and < 6.6.143≥ 5.16 and < 6.1.176 |
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 |
|---|---|---|---|---|---|
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) EPSS over time FIRST
Oct 15, 2026 → Oct 16, 2026 · 2 reading(s) · max 0.13%
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
- Record published
- Fix documented
- CVSS changed · 5.5
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
7 on the record
- git.kernel.org/stable/c/55f2ea9ff83cc27a85526b14bc9b32f96a08d6ec
- git.kernel.org/stable/c/d54a221b0f3cd9e1f03f18104be34e02a8258fae
- git.kernel.org/stable/c/aad4337a21b9ad3ae8d668fa8678d05e26ecbaa8
- git.kernel.org/stable/c/3d1561537237c6cc1db76155183d8bbdac2339f0
- git.kernel.org/stable/c/dc4d5c57e012c2c669793deb1515a57bbc6bf5dd
- git.kernel.org/stable/c/9f0d45d509b434c54da10e01f4ef8086e4583401
- git.kernel.org/stable/c/9708eb50fd7343145b422be852f890212155d845
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 2d
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 2d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 3d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 3d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 3d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 3d
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 CISA SSVC assessment.
- No CWE classification.
- 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-2026-53331 is "slimbus: qcom-ngd-ctrl: Avoid ABBA on tx_lock/ctrl->lock", 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 5.5 describes technical severity. EPSS 0.13% 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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