Bug 2517050 (CVE-2026-74535) - CVE-2026-74535 kernel: Bluetooth: ISO: avoid deadlocks in iso_sock_timeout
Summary: CVE-2026-74535 kernel: Bluetooth: ISO: avoid deadlocks in iso_sock_timeout
Keywords:
Status: NEW
Alias: CVE-2026-74535
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 12:47 UTC by OSIDB Bzimport
Modified: 2026-08-19 17:49 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-08-15 12:47:10 UTC
In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: ISO: avoid deadlocks in iso_sock_timeout

iso_sock_timeout() takes lock_sock, so sync disabling the timer while
holding that lock may deadlock.

iso_sock_timeout() may also run concurrently with iso_conn_del(), which
leads to UAF

        [Task 1]                      [Task hdev->workqueue]
        iso_sock_timeout              iso_conn_del
          iso_conn_hold_unless_zero     iso_chan_del
                           `------------> iso_conn_put
                                      caller frees hcon
          iso_conn_put
            iso_conn_free
              conn->hcon->iso_data = NULL; /* UAF */

Fix the deadlock by removing the disable from the lock_sock sections.
Move the timer from iso_conn to iso_pinfo to decouple it from iso_conn
which may need to be freed in lock_sock section. Convert some of the
clear_timer to disable_timer.

Comment 1 Mauro Matteo Cascella 2026-08-19 17:43:26 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081547-CVE-2026-74535-7c9b@gregkh/T


Note You need to log in before you can comment on or make changes to this bug.