Use-after-free in Linux kernel ALSA snd_pcm_drain() linked stream runtime handling
CVE-2026-43437 is a local use-after-free vulnerability in the Linux kernel ALSA PCM subsystem, specifically in snd_pcm_drain(). In the vulnerable drain loop, the local variable runtime is reassigned to a linked stream's runtime (runtime = s->runtime). After the stream lock is released, the code dereferences fields from that linked runtime, including no_period_wakeup, rate, and buffer_size, without any lock or reference protecting the lifetime of the linked runtime object. A concurrent close() on the linked stream's file descriptor can execute snd_pcm_release_substream() -> snd_pcm_drop() -> pcm_release_private() -> snd_pcm_unlink() -> snd_pcm_detach_substream() -> kfree(runtime), freeing the runtime while snd_pcm_drain() still holds and uses the stale pointer. The fix caches the required runtime fields into local variables while the stream lock is still held and uses those cached values after unlocking, eliminating the stale dereference.
Are you exposed to this one?
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
8 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.
No news coverage yet. Advisories and community discussion only.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.