CVE-2026-99008

Bluetooth: RFCOMM: Fix NULL tty_dev dereference in rfcomm_dev_shutdown

State: Published
Severity: Not scored
Published: Oct 23, 2026
Updated: Oct 30, 2026
Reserved: Sep 25, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: RFCOMM: Fix NULL tty_dev dereference in rfcomm_dev_shutdown

syzbot hit a NULL pointer dereference in rfcomm_dev_shutdown() when an RFCOMM tty is closed.

rfcomm_dev_add() puts the new device on rfcomm_dev_list first and only then registers the tty device and saves it in dev->tty_dev. If that registration fails, dev->tty_dev is never set at all. The device can be looked up in the meantime, so an open() of /dev/rfcommN gets through rfcomm_tty_install() and attaches to it. When that tty is closed again, rfcomm_dev_shutdown() uses dev->tty_dev without checking it:

Oops: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047] RIP: 0010:rfcomm_dev_shutdown+0x48/0xb0 net/bluetooth/rfcomm/tty.c:131 Call Trace: tty_port_shutdown+0x1bf/0x220 drivers/tty/tty_port.c:372 tty_port_close+0x4e/0x150 drivers/tty/tty_port.c:705 tty_release+0x359/0x1670 drivers/tty/tty_io.c:1718 __fput+0x418/0xa50 fs/file_table.c:512

rfcomm_dev_destruct() already copes with a NULL dev->tty_dev. Add the same check to rfcomm_dev_shutdown(), so the tty device is only moved when it was actually registered.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	cad348a17e170451ea8688b532a6ca3e98c63b60 to before b2b915042be073637d9f93dc51ef15fc0685ae8aAffected cad348a17e170451ea8688b532a6ca3e98c63b60 to before a43452d8c1015ac2f0e43ff946be5425427b02ccAffected cad348a17e170451ea8688b532a6ca3e98c63b60 to before 3f6394f6c6d1b6817065d3b402f55d437063a704Affected cad348a17e170451ea8688b532a6ca3e98c63b60 to before d5c372ad03330f02962d4860df4d355ab25487dfAffected cad348a17e170451ea8688b532a6ca3e98c63b60 to before 3fd5164bdb04635caa7942ddb554b0ec699a9433Affected cad348a17e170451ea8688b532a6ca3e98c63b60 to before a661f401f83b8462f2d424e0a1a72b7681e92ea2Affected cad348a17e170451ea8688b532a6ca3e98c63b60 to before d0aef0b0374678153244f162df507106d728af39Affected cad348a17e170451ea8688b532a6ca3e98c63b60 to before 08e90633377f1b2567ab5ad6810b74c552246a07Affected
LinuxLinux	3.12Affected before 3.12Not affected 5.10.273 through 5.10.Not affected 5.15.224 through 5.15.Not affected 6.1.191 through 6.1.Not affected 6.6.160 through 6.6.Not affected 6.12.113 through 6.12.Not affected 6.18.57 through 6.18.Not affected 7.2.11 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

cad348a17e170451ea8688b532a6ca3e98c63b60 to before b2b915042be073637d9f93dc51ef15fc0685ae8aAffected
cad348a17e170451ea8688b532a6ca3e98c63b60 to before a43452d8c1015ac2f0e43ff946be5425427b02ccAffected
cad348a17e170451ea8688b532a6ca3e98c63b60 to before 3f6394f6c6d1b6817065d3b402f55d437063a704Affected
cad348a17e170451ea8688b532a6ca3e98c63b60 to before d5c372ad03330f02962d4860df4d355ab25487dfAffected
cad348a17e170451ea8688b532a6ca3e98c63b60 to before 3fd5164bdb04635caa7942ddb554b0ec699a9433Affected
cad348a17e170451ea8688b532a6ca3e98c63b60 to before a661f401f83b8462f2d424e0a1a72b7681e92ea2Affected
cad348a17e170451ea8688b532a6ca3e98c63b60 to before d0aef0b0374678153244f162df507106d728af39Affected
cad348a17e170451ea8688b532a6ca3e98c63b60 to before 08e90633377f1b2567ab5ad6810b74c552246a07Affected

LinuxLinux

3.12Affected
before 3.12Not affected
5.10.273 through 5.10.*Not affected
5.15.224 through 5.15.*Not affected
6.1.191 through 6.1.*Not affected
6.6.160 through 6.6.*Not affected
6.12.113 through 6.12.*Not affected
6.18.57 through 6.18.*Not affected
7.2.11 through 7.2.*Not affected
7.3 and laterNot affected

References

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