Kernel DMA memory leak via USB disconnect
Published Sep 16, 2026 · Updated Sep 16, 2026
Memory leak in the Linux rtl2832_sdr driver allows local users to retain kernel DMA memory by disconnecting a USB SDR during streaming. In rtl2832_sdr_remove(), the driver clears dev->udev before streaming teardown, causing usb_free_coherent() to skip live buffers and URBs. Reachability requires access to an active RTL2832U stream and device disconnection; each trigger leaves kernel allocations unreclaimed.
Summary
What happened
Memory leak in the Linux rtl2832_sdr driver allows local users to retain kernel DMA memory by disconnecting a USB SDR during streaming. In rtl2832_sdr_remove(), the driver clears dev->udev before streaming teardown, causing usb_free_coherent() to skip live buffers and URBs. Reachability requires access to an active RTL2832U stream and device disconnection; each trigger leaves kernel allocations unreclaimed.
The record
- CVE
- CVE-2026-89881
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.15
- Affected versionversion=771138920eafa399f68d3492c8a75dfeea23474b <034b6a4f9589c04bc3f2bd5125658cd72d3e17c8
- Affected versionversion=771138920eafa399f68d3492c8a75dfeea23474b <053581d4657c6b5289c5de71a4828d313c005189
- Affected versionversion=771138920eafa399f68d3492c8a75dfeea23474b <0ef9f19010ae4ba93aca211ea8f0081b9bf7aab2
- Affected versionversion=771138920eafa399f68d3492c8a75dfeea23474b <234c46b95a032232e31fa5987b84fb8f87a9693b
- Affected versionversion=771138920eafa399f68d3492c8a75dfeea23474b <7443b16b6dd8889a3b9c5236a09e7c58f0d11dae
- Affected versionversion=771138920eafa399f68d3492c8a75dfeea23474b <a0d9d9a3b41a1346c26af57aade6ba3f552fa171
- Affected versionversion=771138920eafa399f68d3492c8a75dfeea23474b <bbf15e83c37d9ac938b7c35c02b748fe54230010
- Affected versionversion=771138920eafa399f68d3492c8a75dfeea23474b <dabb047c62668f280998e29117c55e41aabac336
What conditions does exploitation require?
What is affected?
Published CVSS scores
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CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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