can: isotp: use unconditional synchronize_rcu() in isotp_release()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: can: isotp: use unconditional synchronize_rcu() in isotp_release() isotp_notify() unregisters the (RCU) CAN filters via can_rx_unregister() and clears so->bound without waiting for a grace period. isotp_release() uses so->bound to decide whether it needs to call synchronize_rcu() before cancelling so->rxtimer, so when NETDEV_UNREGISTER runs first it skips that synchronize_rcu() and can cancel the timer while an in-flight isotp_rcv() is still executing and about to re-arm it via isotp_send_fc(), leading to a use-after-free timer callback on the freed socket. sakisho-bot remarked a problem with rtnl_lock held in isotp_notify(), therefore make isotp_release() always call synchronize_rcu() before cancelling the timers, regardless of so->bound. This still closes the original race (isotp_notify() clearing so->bound without waiting for in-flight isotp_rcv() callers before isotp_release() cancels the RX timer) without adding any RCU wait to the netdevice notifier path.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.261, 5.13, 5.14
- Fix · CNA Linux (Linux) Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2026-72126
- 2026-10-03 Alias added: GHSA-5j9g-r9x8-9248
- 2026-10-16 CISA SSVC decision points changed
References
Other 8
- https://git.kernel.org/stable/c/945d9894502cd9124f5d676181c542ed2000f7c0
- https://git.kernel.org/stable/c/59672aa4bcd8d32172c1ff6a179583981d6acabc
- https://git.kernel.org/stable/c/15413a082df69175c2f96aeab4c26fe1ff7cff03
- https://git.kernel.org/stable/c/6280eda96e0707264849fa7d036fed873c1f8a6d
- https://git.kernel.org/stable/c/cb6abc584a1bfab107ac003d64948a4aef1730aa
- https://git.kernel.org/stable/c/b88a511308779c225005d7994b8744561bdbafbc
- https://git.kernel.org/stable/c/b8278ff605187ef3fa0f2705e93251cce4c4f8ee
- https://git.kernel.org/stable/c/9b1a02e0d980ac6b0e36a90378f847062f81d7e4
More Linux vulnerabilities
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- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-72126 · CVE Program
- CVE-2026-72126 · NVD
- FIRST EPSS
- GHSA-5j9g-r9x8-9248 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-72126 · Red Hat security data · CC BY 4.0
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