CVE-2026-74502: ALSA: ump: fix double free of out_cvts on rawmidi error
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ump: fix double free of outcvts on rawmidi error
sndumpattachlegacyrawmidi() allocates the legacy conversion array ump->outcvts and, on the sndrawmidinew() error path, frees it with kfree() but leaves ump->outcvts pointing at the freed memory. When the endpoint is later torn down, sndumpendpointfree() frees ump->outcvts a second time, resulting in a double free.
The host snd-usb-audio driver attaches the legacy rawmidi for any USB MIDI 2.0 (UMP) device, so a device that makes sndrawmidinew() fail reaches this path on enumeration.
Clear ump->outcvts after freeing it on the error path so it is not freed again during teardown.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- 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 6.12.107-1Fixed 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 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.6.151 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.103 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.18.44 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 7.1.8 - Compensating control
In snd_ump_attach_legacy_rawmidi(), set ump->out_cvts to NULL immediately after freeing it with kfree() on the snd_rawmidi_new() error path, preventing snd_ump_endpoint_free() from freeing it again during teardown.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-74502?
CVE-2026-74502 has a risk score of 37, indicating a moderate security threat.
How do I fix CVE-2026-74502?
To fix CVE-2026-74502, upgrade to the patched version of the Linux kernel that addresses the double free vulnerability.
What systems are affected by CVE-2026-74502?
CVE-2026-74502 affects Linux kernel versions utilizing ALSA with legacy rawmidi support.
What type of vulnerability is CVE-2026-74502?
CVE-2026-74502 is classified as a double free vulnerability, which may lead to software crashes or potential exploitation.
When was CVE-2026-74502 published?
CVE-2026-74502 was published on August 15, 2026.