usb: usbfs: fix use-after-free of usb_device in usbdev_release()
Summary
| CVE | CVE-2026-80824 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-04 16:18:10 UTC |
| Updated | 2026-09-04 16:18:10 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: usb: usbfs: fix use-after-free of usb_device in usbdev_release() usbdev_release() drops its reference to the struct usb_device before draining the list of completed async URBs, but that drain path reads back through the same object: free_async() calls dec_usb_memory_use_count() for any URB whose buffer came from the usbfs mmap() region, and its first statement is bus_to_hcd(ps->dev->bus). After a disconnect the usbfs reference can be the last one, in which case usb_put_dev() frees the device and the subsequent loop reads offset 80 of freed memory and uses the result as a struct usb_hcd *, which hcd_buffer_free_pages() then dereferences. This is reachable by an unprivileged process that has read/write access to a /dev/bus/usb node: mmap() the fd, submit one URB with a buffer inside the mapping, wait for the device to be unplugged, then munmap() and close(). It reproduces on every attempt rather than being a race, because a live MAP_SHARED vma holds a reference on the struct file, so usbdev_release() cannot run until the last vma is gone and the freeing branch of dec_usb_memory_use_count() is always taken. BUG: KASAN: slab-use-after-free in dec_usb_memory_use_count+0x3ae/0x410 Read of size 8 at addr ffff8880122ee050 by task poc/769 CPU: 1 UID: 1000 PID: 769 Comm: poc Tainted: G B 6.12.94 #3 Call Trace: dec_usb_memory_use_count+0x3ae/0x410 free_async+0x2aa/0x4f0 usbdev_release+0x375/0x460 __fput+0x3ea/0xb50 __x64_sys_close+0x86/0x100 Allocated by task 11: usb_alloc_dev+0x55/0xd90 hub_event+0x2524/0x43d0 Freed by task 769: kfree+0x121/0x360 device_release+0xd2/0x280 usb_put_dev+0x23/0x30 usbdev_release+0x2d8/0x460 Release the device reference after the drain loop instead. Nothing between the two points requires it to have been dropped. |
Risk And Classification
EPSS: 0.001950000 probability, percentile 0.092810000 (date 2026-09-07)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected f7d34b445abc00e979b7cf36b9580ac3d1a47cd8 0a960b88c5979f853019d4dc4957dfbeeb193440 git | Not specified |
| CNA | Linux | Linux | affected f7d34b445abc00e979b7cf36b9580ac3d1a47cd8 96f5520fc9a5e4bbf77ac93c9d5ce502f597e6cf git | Not specified |
| CNA | Linux | Linux | affected f7d34b445abc00e979b7cf36b9580ac3d1a47cd8 bd4bffc621a8cb2f4d9ed9b6447415de524a3bef git | Not specified |
| CNA | Linux | Linux | affected f7d34b445abc00e979b7cf36b9580ac3d1a47cd8 65879e0a452ca2a234b9475e0c11aff7a4343738 git | Not specified |
| CNA | Linux | Linux | affected f7d34b445abc00e979b7cf36b9580ac3d1a47cd8 b3cde26a66b04f1d90ed0b675899c88b4e49d424 git | Not specified |
| CNA | Linux | Linux | affected f7d34b445abc00e979b7cf36b9580ac3d1a47cd8 5f08c45bdcfd28d1171de38c5ef29fc89a76eedc git | Not specified |
| CNA | Linux | Linux | affected f7d34b445abc00e979b7cf36b9580ac3d1a47cd8 7f0278e474c4d1c4457974ff1137cc385c944ab3 git | Not specified |
| CNA | Linux | Linux | affected f7d34b445abc00e979b7cf36b9580ac3d1a47cd8 47a7f98fbb5006d46d15a3a210ffdc61448a4f19 git | Not specified |
| CNA | Linux | Linux | affected f7d34b445abc00e979b7cf36b9580ac3d1a47cd8 0dd68b5d01d022fc9c5e71c82a82b0a94d3d0671 git | Not specified |
| CNA | Linux | Linux | affected 4.6 | Not specified |
| CNA | Linux | Linux | unaffected 4.6 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.269 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.220 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.187 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.156 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.108 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.49 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.13 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.3 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/47a7f98fbb5006d46d15a3a210ffdc61448a4f19 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/bd4bffc621a8cb2f4d9ed9b6447415de524a3bef | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/7f0278e474c4d1c4457974ff1137cc385c944ab3 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b3cde26a66b04f1d90ed0b675899c88b4e49d424 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/96f5520fc9a5e4bbf77ac93c9d5ce502f597e6cf | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5f08c45bdcfd28d1171de38c5ef29fc89a76eedc | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0a960b88c5979f853019d4dc4957dfbeeb193440 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/65879e0a452ca2a234b9475e0c11aff7a4343738 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0dd68b5d01d022fc9c5e71c82a82b0a94d3d0671 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.