CVE-2026-31772
- Source
- https://cve.org/CVERecord?id=CVE-2026-31772
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31772.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-31772
- Downstream
BELL (1)
DEBIAN (1)
openSUSE (1)
RLSA (2)
SUSE (5)
- Related
- Published
- 2026-05-01T14:15:00Z
- Modified
- 2026-10-20T10:30:46Z
- Severity
-
- 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
- Summary
- Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync
hci_le_big_create_sync() uses DEFINE_FLEX to allocate a struct hci_cp_le_big_create_sync on the stack with room for 0x11 (17) BIS entries. However, conn->num_bis can hold up to HCI_MAX_ISO_BIS (31) entries — validated against ISO_MAX_NUM_BIS (0x1f) in the caller hci_conn_big_create_sync(). When conn->num_bis is between 18 and 31, the memcpy that copies conn->bis into cp->bis writes up to 14 bytes past the stack buffer, corrupting adjacent stack memory.
This is trivially reproducible: binding an ISO socket with bc_num_bis = ISO_MAX_NUM_BIS (31) and calling listen() will eventually trigger hci_le_big_create_sync() from the HCI command sync worker, causing a KASAN-detectable stack-out-of-bounds write:
BUG: KASAN: stack-out-of-bounds in hci_le_big_create_sync+0x256/0x3b0 Write of size 31 at addr ffffc90000487b48 by task kworker/u9:0/71
Fix this by changing the DEFINE_FLEX count from the incorrect 0x11 to HCI_MAX_ISO_BIS, which matches the maximum number of BIS entries that conn->bis can actually carry.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31772.json" }- References
-
- https://git.kernel.org/stable/c/aba0aea354015794e8312dd7efe726967e58aefe
- https://git.kernel.org/stable/c/bc39a094730ce062fa034a529c93147c096cb488
- https://git.kernel.org/stable/c/eaf32002ca7b1ba51c9f140991fd9febe6de79f0
- https://git.kernel.org/stable/c/f5d446624345d309e7a4a1b27ea9f028d6a8c5d9
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31772.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-31772
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced91d19383b7ed035e22165ae5c836e50bb9f95fbeFixedf5d446624345d309e7a4a1b27ea9f028d6a8c5d9
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced42ecf1947135110ea08abeaca39741636f9a2285Fixedaba0aea354015794e8312dd7efe726967e58aefeFixedeaf32002ca7b1ba51c9f140991fd9febe6de79f0Fixedbc39a094730ce062fa034a529c93147c096cb488
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced6.12.2Fixed6.12.81
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced6.11.11Fixed6.12
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced8958e1cee4e2eac1a5b825caa4dd96ce9ed975dd