CVE Catalog

CVE-2026-90220

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the ALSA seq bounce_error_event() embeds a data.ext.ptr pointer in the bounce payload that reaches userspace. This leaks a kernel address (8 bytes on 64-bit) even though the event header read path clears it.

Risk Assessment

An unprivileged client can leak a kernel memory address, aiding ASLR bypass and further exploitation.

Recommendation

Update the Linux kernel to a version containing the fix that embeds a sanitised copy of the event instead of the original pointer.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Don't leak the extension cell pointer in the bounce payload The bounce_error_event() embeds the failed event in the bounce payload by pointing data.ext.ptr at it. When that event is a queued variable-length event, its own data.ext.ptr holds the address of its first extension cell, put there by snd_seq_event_dup(). The payload goes out verbatim through snd_seq_expand_var_event(), so the address reaches userspace. That is the same address commit 705dd6dcbc0e ("ALSA: seq: Clear variable event pointer on read") removed from the event header. The read path still clears it there, just above the call that expands the payload. Embed a sanitised copy instead, treated exactly as snd_seq_read() treats the header. A stack copy is enough because delivery is synchronous and snd_seq_event_dup() copies before returning. An unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE, queueing a variable-length event to a port that does not exist and reading the bounce back. Eight bytes on 64-bit, from its own pool.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS