In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: Fix session UAF in set_termios
rfcomm_tty_set_termios() tests dlc->session without rfcomm_mutex and later passes the pointer to rfcomm_send_rpn(). The latter dereferences both session->initiator and session->sock. Meanwhile, krfcommd can unlink the DLC and free the session while holding rfcomm_mutex.
The race can proceed as follows:
TTY ioctl task krfcommd -------------- -------- load dlc->session enter rfcomm_send_rpn() lock rfcomm_mutex clear dlc->session free session unlock rfcomm_mutex read session->initiator
KASAN reported:
BUG: KASAN: slab-use-after-free in rfcomm_send_rpn+0x297/0x2a0 Read of size 4 at addr ffff88810012a850 by task poc/92
Call Trace: rfcomm_send_rpn+0x297/0x2a0 rfcomm_tty_set_termios+0x50d/0x850 tty_set_termios+0x596/0x950 set_termios+0x46a/0x6e0 tty_mode_ioctl+0x152/0xbd0 tty_ioctl+0x915/0x1240 __x64_sys_ioctl+0x134/0x1c0
Allocated by task 92: rfcomm_session_add+0x9e/0x2e0 rfcomm_dlc_open+0x8b1/0xe00 rfcomm_dev_activate+0x85/0x1a0 rfcomm_tty_open+0x90/0x280
Freed by task 68: kfree+0x131/0x3c0 rfcomm_session_del+0x119/0x180 rfcomm_run+0x737/0x4710
Add rfcomm_dlc_send_rpn(), which holds rfcomm_mutex while it verifies that the DLC is still attached and sends the RPN frame. Have the TTY path use the helper and drop its unlocked session check. This keeps the session valid through both the frame construction and socket send.
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linuxUpgrade linux-6.12 | Aug 11, 2026 | Aug 11, 2026 |
| Redhat_linux | — | Upgrade kernel-rtUpgrade kernelNo solution exists | Aug 13, 2026 | Aug 10, 2026 |
| Rocky_linux | — | Upgrade kernel-zfcpdump-develUpgrade kernel-modulesUpgrade kernel-zfcpdump-debuginfoUpgrade python3-perfUpgrade kernel-rt-modules-coreUpgrade kernel-rt-debug-modules-extraUpgrade kernel-modules-coreUpgrade kernel-devel-matchedUpgrade libperf-debuginfoUpgrade libperfUpgrade kernel-tools-libs-develUpgrade kernel-uki-virtUpgrade perf-debuginfoUpgrade kernel-zfcpdump-modulesUpgrade kernel-rt-debug-develUpgrade kernel-rt-debug-modules-coreUpgrade kernel-rt-modulesUpgrade perfUpgrade kernel-rt-debug-kvmUpgrade kernel-debug-modules-extraUpgrade kernel-zfcpdump-coreUpgrade kernel-debug-devel-matchedUpgrade kernel-zfcpdump-modules-coreUpgrade kernel-debuginfo-common-s390xUpgrade kernel-debug-develUpgrade rtlaUpgrade kernel-debuginfoUpgrade python3-perf-debuginfoUpgrade kernel-rt-debuginfo-common-x86_64Upgrade kernel-rt-debug-debuginfoUpgrade kernel-rtUpgrade kernel-develUpgrade kernel-debug-coreUpgrade kernel-debug-debuginfoUpgrade kernelUpgrade kernel-rt-modules-extraUpgrade kernel-rt-debug-coreUpgrade kernel-rt-debug-modulesUpgrade kernel-rt-kvmUpgrade kernel-rt-debugUpgrade kernel-rt-coreUpgrade kernel-modules-extraUpgrade bpftoolUpgrade kernel-rt-develUpgrade kernel-rt-debuginfoUpgrade kernel-modules-extra-matchedUpgrade kernel-debuginfo-common-x86_64Upgrade rvUpgrade kernel-zfcpdump-modules-extraUpgrade kernel-tools-debuginfoUpgrade kernel-debug-modules-coreUpgrade kernel-debug-uki-virtUpgrade kernel-debug-modulesUpgrade kernel-tools-libsUpgrade kernel-debugUpgrade kernel-zfcpdump-devel-matchedUpgrade kernel-toolsUpgrade kernel-zfcpdumpUpgrade bpftool-debuginfoUpgrade kernel-uki-virt-addonsUpgrade kernel-core | Sep 28, 2026 | Sep 24, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Aug 17, 2026 | Aug 10, 2026 |
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