CVE-2026-31772
published 2026-05-01CVE-2026-31772: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync…
PriorityP342high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.14%
3.9th percentile
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.
Affected
15 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | — | — |
| linux | linux | >= 42ecf1947135110ea08abeaca39741636f9a2285 < aba0aea354015794e8312dd7efe726967e58aefe | aba0aea354015794e8312dd7efe726967e58aefe |
| linux | linux | >= 42ecf1947135110ea08abeaca39741636f9a2285 < eaf32002ca7b1ba51c9f140991fd9febe6de79f0 | eaf32002ca7b1ba51c9f140991fd9febe6de79f0 |
| linux | linux | >= 42ecf1947135110ea08abeaca39741636f9a2285 < bc39a094730ce062fa034a529c93147c096cb488 | bc39a094730ce062fa034a529c93147c096cb488 |
| linux | linux | >= 6.11.11 < 6.12 | 6.12 |
| linux | linux | >= 6.12.2 < 6.12.81 | 6.12.81 |
| linux | linux | >= 91d19383b7ed035e22165ae5c836e50bb9f95fbe < f5d446624345d309e7a4a1b27ea9f028d6a8c5d9 | f5d446624345d309e7a4a1b27ea9f028d6a8c5d9 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 6.11.11 < 6.12 | 6.12 |
| linux | linux_kernel | >= 6.12.2 < 6.12.81 | 6.12.81 |
| linux | linux_kernel | >= 6.13.1 < 6.18.22 | 6.18.22 |
| linux | linux_kernel | >= 6.19 < 6.19.12 | 6.19.12 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vendor_redhat7.0HIGH
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Red Hat
kernel: Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync
vendor_redhat·2026-05-01·CVSS 7.0
CVE-2026-31772 [HIGH] CWE-787 kernel: Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync
kernel: Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync
A flaw was found in the Linux kernel's Bluetooth Host Controller Interface (HCI) synchronization. A local user could trigger a stack buffer overflow by binding a specific type of Bluetooth socket with an excessive number of Bluetooth Isochronous Stream (BIS) entries. This memory corruption can lead to a system crash, resulting in a denial of service.
Package: kernel (Red Hat Enterprise Linux 10) - Affected
Package: kernel (Red Hat Enterprise Linux 6) - Not affected
Package: kernel (Red Hat Enterprise Linux 7) - Not affected
Package: kernel-rt (Red Hat Enterprise Linux 7) - Not affected
Package: kernel (Red Hat Enterprise Linux 8) - Not affected
Package: kernel-rt (Red Hat Enterprise Linux 8) - Not affec
GHSA
GHSA-9f4r-27xr-gwq3: 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_
ghsa_unreviewed·2026-05-01
CVE-2026-31772 [HIGH] GHSA-9f4r-27xr-gwq3: 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_
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, ca
No detection rules found.
No public exploits indexed.
2026-05-01
Published