Bluetooth: hci_core: Fix use-after-free in vhci_flush()
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: Fix use-after-free in vhci_flush() syzbot reported use-after-free in vhci_flush() without repro. [0] From the splat, a thread close()d a vhci file descriptor while its device was being used by iotcl() on another thread. Once the last fd refcnt is released, vhci_release() calls hci_unregister_dev(), hci_free_dev(), and kfree() for struct vhci_data, which is set to hci_dev->dev->driver_data. The problem is that there is no synchronisation after unlinking hdev from hci_dev_list in hci_unregister_dev(). There might be another thread still accessing the hdev which was fetched before the unlink operation. We can use SRCU for such synchronisation. Let's run hci_dev_reset() under SRCU and wait for its completion in hci_unregister_dev(). Another option would be to restore hci_dev->destruct(), which was removed in commit 587ae086f6e4 ("Bluetooth: Remove unused hci-destruct cb"). However, this would not be a good solution, as we should not run hci_unregister_dev() while there are in-flight ioctl() requests, which could lead to another data-race KCSAN splat. Note that other drivers seem to have the same problem, for exmaple, virtbt_remove(). [0]: BUG: KASAN: slab-use-after-free in skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline] BUG: KASAN: slab-use-after-free in skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937 Read of size 8 at addr ffff88807cb8d858 by task syz.1.219/6718 CPU: 1
CVE-2025-38250
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2025-38250
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f",
"lessThan": "dd4becd3fd4102696e1c15e6d260a1712a2d8685",
"versionType": "git"
},
{
"status": "affected",
"version": "bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f",
"lessThan": "90dee0a0ff84fac8accd5be98412b3819f667149",
"versionType": "git"
},
{
"status": "affected",
"version": "bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f",
"lessThan": "c56b177efce8b62798e4d96bdb9867106cb7c4a0",
"versionType": "git"
},
{
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"lessThan": "bc0819a25e04cd68ef3568cfa51b63118fea39a7",
"versionType": "git"
},
{
"status": "affected",
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"lessThan": "ce23b73f0f27e2dbeb81734a79db710f05aa33c6",
"versionType": "git"
},
{
"status": "affected",
"version": "bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f",
"lessThan": "0e5c144c557df910ab64d9c25d06399a9a735e65",
"versionType": "git"
},
{
"status": "affected",
"version": "bf18c7118cf83ad4b9aa476354b4a06bcb9d0c4f",
"lessThan": "1d6123102e9fbedc8d25bf4731da6d513173e49e",
"versionType": "git"
}
],
"programFiles": [
"include/net/bluetooth/hci_core.h",
"net/bluetooth/hci_core.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.4"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.4",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.259",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.209",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.167",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.97",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.36",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.15.5",
"versionType": "semver",
"lessThanOrEqual": "6.15.*"
},
{
"status": "unaffected",
"version": "6.16",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/net/bluetooth/hci_core.h",
"net/bluetooth/hci_core.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-38250
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #30549 · Revision 1
- Added to Heist Feed
- Publisher date