# CVE-2026-72073: mmc: vub300: fix use-after-free on probe failure CVE-2026-72073 is fixed in 30 products on 1 platform, first by DEBIAN-CVE-2026-72073, released August 15, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-72073 - Priority: Routine - CVSS: 6.3 (Moderate) - EPSS: 0.0022 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 15, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72073 ## Description In the Linux kernel, the following vulnerability has been resolved: mmc: vub300: fix use-after-free on probe failure The vub300 driver lifetime-manages its controller state using vub300->kref, with vub300_delete() freeing the mmc host when the last reference is dropped. The probe error path after the inactivity timer has been armed still bypasses that lifetime rule, however, and falls through to mmc_free_host() directly if mmc_add_host() fails. The race window is between arming the inactivity timer and reaching the probe error unwind after mmc_add_host() fails: probe thread timer/workqueue ------------ --------------- kref_init(&vub300->kref) ref = 1 kref_get(&vub300->kref) ref = 2, timer ref add_timer(inactivity_timer) fires after one second | | race window |<----------------------------------------------------> | mmc_add_host(mmc) inactivity timer fires vub300_queue_dead_work() kref_get() ref = 3 queue_work(deadwork) mmc_add_host() fails timer_delete_sync() mmc_free_host(mmc) frees vub300 deadwork runs use-after-free The inactivity timeout is one second, so this would require mmc_add_host() to both fail and take more than one second to do so. This is unlikely to happen in practice, but the error path is still wrong. timer_delete_sync() only waits for the timer callback itself. It does not flush deadwork that the callback may already have queued. As a result, queued deadwork can still hold a kref while the probe error path directly frees the backing mmc host, including the vub300 storage. Fix this by using the same lifetime mechanism as disconnect. Clear vub300->interface so that the timer callback and any queued deadwork return early and drop their references, then drop the initial probe reference and return without falling through to err_free_host. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | bpftool ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.90.1.150700.17.51.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_24 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | kernel-uek ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-container ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-container ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-container-debug ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-container-debug ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-core ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-core ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug-core ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug-core ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug-devel ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug-devel ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug-modules ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug-modules ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug-modules-extra ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-debug-modules-extra ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-devel ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-devel ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-doc ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-doc ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-modules ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-modules ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-modules-extra ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek-modules-extra ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k-core ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k-core ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k-devel ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k-devel ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k-modules ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k-modules ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k-modules-extra ol 8 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-uek64k-modules-extra ol 9 | 0:5.15.0-324.217.5.2.el9uek | [ELSA-2026-500249](https://patchblox.com/security/data/fix/linux/elsa-2026-500249.md) | Sep 4, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-72073](https://patchblox.com/security/data/fix/linux/debian-cve-2026-72073.md) | Aug 15, 2026 | | Linux | linux Debian 14 | 7.1.5-1 | [DEBIAN-CVE-2026-72073](https://patchblox.com/security/data/fix/linux/debian-cve-2026-72073.md) | Aug 15, 2026 | --- Data as of 2026-11-08T00:53:09Z UTC. 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