Kernel crash via unlocked RFCOMM deferred accept
Published Sep 4, 2026 · Updated Sep 4, 2026
NULL pointer dereference in Linux kernel RFCOMM allows physically proximate attackers to crash the kernel through a Bluetooth peer. rfcomm_sock_recvmsg calls rfcomm_dlc_accept without rfcomm_mutex after a DISC can unlink the session while leaving RFCOMM_DEFER_SETUP set, causing an unconditional NULL session dereference. The peer must reach a socket using deferred setup and send DISC after acceptance; the next local receive operation faults without requiring a timing race.
Summary
What happened
NULL pointer dereference in Linux kernel RFCOMM allows physically proximate attackers to crash the kernel through a Bluetooth peer. rfcomm_sock_recvmsg calls rfcomm_dlc_accept without rfcomm_mutex after a DISC can unlink the session while leaving RFCOMM_DEFER_SETUP set, causing an unconditional NULL session dereference. The peer must reach a socket using deferred setup and send DISC after acceptance; the next local receive operation faults without requiring a timing race.
The record
- CVE
- CVE-2026-80819
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-476, T1499.004
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 4, 2026CVE publishedPublication date reported by the CVE source.
- Sep 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=2.6.30
- Affected versionversion=bb23c0ab824653be4aa7dfca15b07b3059717004 <355bfd57ca4ca881c6eb03ca813b440a094b1f44
- Affected versionversion=bb23c0ab824653be4aa7dfca15b07b3059717004 <362726c9c6e56eea4262109183e49868c39ccd3a
- Affected versionversion=bb23c0ab824653be4aa7dfca15b07b3059717004 <43a556b2fd43f2df6dded59c2e26560a27874c24
- Affected versionversion=bb23c0ab824653be4aa7dfca15b07b3059717004 <56f0aa75c7640e46397ef73bea251fcbef9150c0
- Affected versionversion=bb23c0ab824653be4aa7dfca15b07b3059717004 <825b95561d7b7c393df9e7bc295451aaeadc3d18
- Affected versionversion=bb23c0ab824653be4aa7dfca15b07b3059717004 <b405c2f96ae2e37375105881890f7738833b1d62
- Affected versionversion=bb23c0ab824653be4aa7dfca15b07b3059717004 <d4b1a13b1eff2e80925c7368ffdeaaa50cba93df
- Affected versionversion=bb23c0ab824653be4aa7dfca15b07b3059717004 <d8d686dd5662a7c4745e4515f1237a9f3b7df181
- Affected versionversion=bb23c0ab824653be4aa7dfca15b07b3059717004 <eb71d5a1ea8ff2683e394b48ae3cd676037ab4c2
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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