CVE-2026-74536: Bluetooth: ISO: fix leaking sk after socket release
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: fix leaking sk after socket release
isosockkill() tests !sockflag(sk, SOCKZAPPED) || sk->sksocket || sockflag(sk, SOCKDEAD) for early return, but this is always true since sockorphan(sk) sets SOCKDEAD, so the sk reference released by socket always leaks, isosockdestruct is never called.
The socket reference also leaks when isosockclose() does not set SOCKZAPPED, since isoconndel() does not call isosockkill() after zapping.
Fix by replacing SOCKDEAD by BTSKKILLED flag that is not used for something else, and locksock to ensure isosockkill() puts sk only after socket release only once. Release and isoconndel may run concurrently. Call isosockkill() from isoconndel() to clean sk up after zapping.
Remove call to isosockkill() from isosockclose(), as it's generally no-op there.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-74536?
CVE-2026-74536 has a risk severity rating of 27.
How do I fix CVE-2026-74536?
To fix CVE-2026-74536, update to the latest version of the Linux kernel that addresses this vulnerability.
What systems are affected by CVE-2026-74536?
CVE-2026-74536 affects the Bluetooth ISO subsystem in the Linux kernel.
What are the potential impacts of CVE-2026-74536?
CVE-2026-74536 may lead to resource leakage due to improper handling of socket flags.
When was CVE-2026-74536 published?
CVE-2026-74536 was published on August 15, 2026.