CVE-2026-98086: ALSA: ump: do not touch legacy_rmidi before it exists
ALSA: ump: do not touch legacyrmidi before it exists
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.158.1-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.113-1~deb12u1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Compensating control
Guard legacy helper calls so UMP packet handling does not access or update ump->legacy_rmidi until the legacy rawMIDI device has been attached and legacy_rmidi is non-NULL.
Event History
Frequently Asked Questions
What systems are exposed to this issue?
Systems using the Linux kernel ALSA UMP path are exposed when a UMP packet can be received during endpoint setup, before the legacy rawmidi device has been attached.
What does an attacker or triggering condition need to exploit it?
A UMP packet must arrive through the snd_ump_receive IRQ path after endpoint parsing has completed but before legacy_rmidi is created. In that window, processing an endpoint-name message can dereference a NULL legacy_rmidi pointer.
How can I tell whether the vulnerable condition occurred?
The described failure manifests as a KASAN-detected NULL-pointer dereference in snprintf(), reached through ump_legacy_set_rawmidi_name() while handling a UMP endpoint-name message.