CVE-2026-98739Bluetooth: RFCOMM: Fix initial port reference race
Updated under an hour ago ()
Does this affect you?
It affects Linux. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: Fix initial port reference race For RFCOMM_RELEASE_ONHUP devices, rfcomm_tty_install() and __rfcomm_release_dev() both use RFCOMM_TTY_OWNED to decide who drops the initial tty_port reference. The release path tests the bit separately from the install path setting it, so both can drop that reference. The synchronous hangup does not prevent this race: port->tty is not assigned until tty_port_open(), after installation. The following interleaving is possible: 1. Install and release each obtain a reference with rfcomm_dev_get(). 2. Release observes RFCOMM_TTY_OWNED clear. 3. Install sets RFCOMM_TTY_OWNED and drops the initial reference. 4. Release drops the same initial reference again. 5. TTY cleanup drops its reference and frees the device. 6. Release performs its final tty_port_put() on the freed port. KASAN reported: BUG: KASAN: slab-use-after-free in tty_port_put+0x22/0x190 Write of size 4 at addr ffff8881001d3d5c by task poc/92 Call Trace: tty_port_put+0x22/0x190 rfcomm_dev_ioctl+0x1d4/0x1930 sock_do_ioctl+0x110/0x260 sock_ioctl+0x380/0x590 __x64_sys_ioctl+0x134/0x1c0 Allocated by task 88: rfcomm_dev_ioctl+0x8f6/0x1930 sock_do_ioctl+0x110/0x260 sock_ioctl+0x380/0x590 __x64_sys_ioctl+0x134/0x1c0 Freed by task 65: kfree+0x131/0x3c0 rfcomm_dev_destruct+0x23b/0x2f0 release_one_tty+0xc1/0x370 process_one_work+0x661/0x1090 Use test_and_set_bit() in both paths so that only the caller that changes RFCOMM_TTY_OWNED from clear to set drops the initial reference. Each path keeps its own lookup reference until release or TTY cleanup, preserving the existing callback ordering and error handling.
- CVSS
- Not yet scored
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 18, 2026
- First seen by InfoSec Signals
- Oct 18, 2026
Affected products
Linux Linux linux:linux (from the name) | from 80ea73378af46b0023eb2f400d26c2a60248ffaa before a03ccf1ab77380d4c4a3c56552e12de4a83efa21; 80ea73378af46b0023eb2f400d26c2a60248ffaa builds before 0a554901bd227537f79220443b2b36d585d62893; from 80ea73378af46b0023eb2f400d26c2a60248ffaa before e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b; 80ea73378af46b0023eb2f400d26c2a60248ffaa builds before 2d696c1ed3468dcb62578a3911e687110d463520 | CNA record |
References
- https://git.kernel.org/stable/c/a03ccf1ab77380d4c4a3c56552e12de4a83efa21
- https://git.kernel.org/stable/c/0a554901bd227537f79220443b2b36d585d62893
- https://git.kernel.org/stable/c/e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b
- https://git.kernel.org/stable/c/2d696c1ed3468dcb62578a3911e687110d463520
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.