CVE-2026-63871: Bluetooth: ISO: Fix data-race on iso_pi fields in hci_get_route calls
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: Fix data-race on isopi fields in hcigetroute calls
isoconnectbis(), isoconnectcis(), isolistenbis(), and isoconnbigsync() call hcigetroute() using isopi(sk)->dst, isopi(sk)->src, and isopi(sk)->srctype without holding locksock().
These fields may be modified concurrently by connect() or setsockopt() on the same socket, resulting in data-races reported by KCSAN.
Fix this by snapshotting the required fields under locksock() before calling hcigetroute().
BUG: KCSAN: data-race in memcmp+0x45/0xb0
race at unknown origin, with read to 0xffff8880122135cf of 1 bytes by task 333 on cpu 1: memcmp+0x45/0xb0 hcigetroute+0x27e/0x490 isoconnectcis+0x4c/0xa10 isosockconnect+0x60e/0xb30 sysconnectfile+0xbd/0xe0 sysconnect+0xe0/0x110 x64sysconnect+0x40/0x50 x64syscall+0xcad/0x1c60 dosyscall64+0x133/0x590 entrySYSCALL64afterhwframe+0x77/0x7f
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-63871?
The severity of CVE-2026-63871 is rated at 12.
How do I fix CVE-2026-63871?
To fix CVE-2026-63871, update to the latest version of the Linux kernel where this vulnerability has been addressed.
What systems are affected by CVE-2026-63871?
CVE-2026-63871 affects the Bluetooth stack within the Linux kernel.
What types of calls are impacted by CVE-2026-63871?
CVE-2026-63871 affects calls to iso_connect_bis(), iso_connect_cis(), iso_listen_bis(), and iso_conn_big_sync() that use hci_get_route().
What is the nature of the issue in CVE-2026-63871?
CVE-2026-63871 is related to a data-race condition on iso_pi fields in hci_get_route calls.