UBUNTU-CVE-2026-80556: Use After Free
In the Linux kernel, the following vulnerability has been resolved: mmc: atmel-mci: Fix use-after-free in atmciremove due to race condition In atmciprobe, &host->bhwork is bound with atmciworkfunc, and atmciinterrupt, atmcitimeouttimer and atmcidmacomplete can all queue this work on systembhwq. If we remove the module, atmciremove makes cleanup and the memory allocated for host with devmkzalloc() is released after the remove callback returns, while the work mentioned above may still be pending or running. The sequence of operations that may lead to a UAF bug is as follows: CPU0 CPU1 | atmciinterrupt | queuework(systembhwq, | &host->bhwork) atmciremove | atmcicleanupslot(...) | atmciwritel(host, ATMCIIDR, ~0UL) | timerdeletesync(&host->timer) | dmareleasechannel(host->dma.chan) | freeirq(platformgetirq(pdev, 0), host) | | atmciworkfunc | // use host // devm resources released after | // remove returns, host is freed | | // use host (use-after-free) Fix it by canceling the work after all the sources that can schedule it (IRQ handler, timeout timer and DMA completion callback) have been stopped, and before proceeding with the remaining cleanup in atmciremove.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
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-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1036.39 - 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
In atmci_remove, stop all sources that can schedule &host->bh_work (the IRQ handler, timeout timer, and DMA completion callback), then cancel the work before proceeding with the remaining cleanup.