virtio: fix use-after-free in unregister_virtio_device()
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.12.111, 6.18.53, 7.2.7
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: virtio: fix use-after-free in unregister_virtio_device() device_unregister() is device_del() plus put_device(). When the caller holds no extra reference, that drops the last one and runs the release callback, which for several transports frees the memory the embedded struct virtio_device sits in. unregister_virtio_device() then calls virtio_debug_device_exit(), which reads dev->debugfs_dir out of the freed object. Affected transports are the ones whose release callback frees and whose remove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml, mlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because virtio_pci_remove() brackets the call with get_device() and put_device(). Remove the debugfs entries before the device can go away. They are only accessed through the protected debugfs interface, so debugfs_remove_recursive() waits for in-progress file operations before returning. Tearing them down while the device is still alive is therefore safe. Reproduced on User-Mode Linux with CONFIG_KASAN and CONFIG_VIRTIO_DEBUG by unbinding a virtio-uml device: BUG: KASAN: slab-use-after-free in virtio_debug_device_exit+0x36/0x4d Read of size 8 at addr 00000000616e0b10 by task init/1 __asan_report_load8_noabort virtio_debug_device_exit+0x36/0x4d unregister_virtio_device+0x48/0x75 virtio_uml_remove platform_remove device_release_driver_internal unbind_store Freed by task 1: kfree virtio_uml_release_dev device_release kobject_put put_device device_unregister With this applied, the report is gone and unbind is clean.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 96a8326d69fffd7e8c2eb737dc060d8009a33b39 · fixed in 951cad50cba89e736afdee4a730e0e52f9245c9b; From 96a8326d69fffd7e8c2eb737dc060d8009a33b39 · fixed in 77dbd10a701a30fdfea5c3bb7a29163128f9a9c7; From 96a8326d69fffd7e8c2eb737dc060d8009a33b39 · fixed in caf042153016d651b55d0fb4a63cdf7d0d23dee2; From 96a8326d69fffd7e8c2eb737dc060d8009a33b39 · fixed in 3f9a0fceb730f5107d52421ead5568eae25a0049
- Linux Linux
6.10
- KernelLinux
From 6.10.0 · fixed in 6.12.111; From 6.13.0 · fixed in 6.18.53; From 6.19.0 · fixed in 7.2.7