| From bippy-7c5fe7eed585 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-21969: Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd |
| |
| After the hci sync command releases l2cap_conn, the hci receive data work |
| queue references the released l2cap_conn when sending to the upper layer. |
| Add hci dev lock to the hci receive data work queue to synchronize the two. |
| |
| [1] |
| BUG: KASAN: slab-use-after-free in l2cap_send_cmd+0x187/0x8d0 net/bluetooth/l2cap_core.c:954 |
| Read of size 8 at addr ffff8880271a4000 by task kworker/u9:2/5837 |
| |
| CPU: 0 UID: 0 PID: 5837 Comm: kworker/u9:2 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 |
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 |
| Workqueue: hci1 hci_rx_work |
| Call Trace: |
| <TASK> |
| __dump_stack lib/dump_stack.c:94 [inline] |
| dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 |
| print_address_description mm/kasan/report.c:378 [inline] |
| print_report+0x169/0x550 mm/kasan/report.c:489 |
| kasan_report+0x143/0x180 mm/kasan/report.c:602 |
| l2cap_build_cmd net/bluetooth/l2cap_core.c:2964 [inline] |
| l2cap_send_cmd+0x187/0x8d0 net/bluetooth/l2cap_core.c:954 |
| l2cap_sig_send_rej net/bluetooth/l2cap_core.c:5502 [inline] |
| l2cap_sig_channel net/bluetooth/l2cap_core.c:5538 [inline] |
| l2cap_recv_frame+0x221f/0x10db0 net/bluetooth/l2cap_core.c:6817 |
| hci_acldata_packet net/bluetooth/hci_core.c:3797 [inline] |
| hci_rx_work+0x508/0xdb0 net/bluetooth/hci_core.c:4040 |
| process_one_work kernel/workqueue.c:3229 [inline] |
| process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 |
| worker_thread+0x870/0xd30 kernel/workqueue.c:3391 |
| kthread+0x2f0/0x390 kernel/kthread.c:389 |
| ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 |
| ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 |
| </TASK> |
| |
| Allocated by task 5837: |
| kasan_save_stack mm/kasan/common.c:47 [inline] |
| kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 |
| poison_kmalloc_redzone mm/kasan/common.c:377 [inline] |
| __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 |
| kasan_kmalloc include/linux/kasan.h:260 [inline] |
| __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329 |
| kmalloc_noprof include/linux/slab.h:901 [inline] |
| kzalloc_noprof include/linux/slab.h:1037 [inline] |
| l2cap_conn_add+0xa9/0x8e0 net/bluetooth/l2cap_core.c:6860 |
| l2cap_connect_cfm+0x115/0x1090 net/bluetooth/l2cap_core.c:7239 |
| hci_connect_cfm include/net/bluetooth/hci_core.h:2057 [inline] |
| hci_remote_features_evt+0x68e/0xac0 net/bluetooth/hci_event.c:3726 |
| hci_event_func net/bluetooth/hci_event.c:7473 [inline] |
| hci_event_packet+0xac2/0x1540 net/bluetooth/hci_event.c:7525 |
| hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4035 |
| process_one_work kernel/workqueue.c:3229 [inline] |
| process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 |
| worker_thread+0x870/0xd30 kernel/workqueue.c:3391 |
| kthread+0x2f0/0x390 kernel/kthread.c:389 |
| ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 |
| ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 |
| |
| Freed by task 54: |
| kasan_save_stack mm/kasan/common.c:47 [inline] |
| kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 |
| kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 |
| poison_slab_object mm/kasan/common.c:247 [inline] |
| __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 |
| kasan_slab_free include/linux/kasan.h:233 [inline] |
| slab_free_hook mm/slub.c:2353 [inline] |
| slab_free mm/slub.c:4613 [inline] |
| kfree+0x196/0x430 mm/slub.c:4761 |
| l2cap_connect_cfm+0xcc/0x1090 net/bluetooth/l2cap_core.c:7235 |
| hci_connect_cfm include/net/bluetooth/hci_core.h:2057 [inline] |
| hci_conn_failed+0x287/0x400 net/bluetooth/hci_conn.c:1266 |
| hci_abort_conn_sync+0x56c/0x11f0 net/bluetooth/hci_sync.c:5603 |
| hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:332 |
| process_one_work kernel/workqueue.c:3229 [inline] |
| process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 |
| worker_thread+0x870/0xd30 kernel/workqueue.c:3391 |
| kthread+0x2f0/0x390 kernel/kthread.c:389 |
| ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 |
| ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 |
| |
| The Linux kernel CVE team has assigned CVE-2025-21969 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 6.6.84 with commit c96cce853542b3b13da3738f35ef1be8cfcc9d1d |
| Fixed in 6.12.20 with commit f8094625a591eeb0b75b1bd9e713fac1d93f5ca9 |
| Fixed in 6.13.8 with commit 7790a79c6fce8d5d552bc64f5c82819f719e4f28 |
| Fixed in 6.14 with commit b4f82f9ed43aefa79bec2504ae8c29be0c0f5d1d |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-21969 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| net/bluetooth/l2cap_core.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/c96cce853542b3b13da3738f35ef1be8cfcc9d1d |
| https://git.kernel.org/stable/c/f8094625a591eeb0b75b1bd9e713fac1d93f5ca9 |
| https://git.kernel.org/stable/c/7790a79c6fce8d5d552bc64f5c82819f719e4f28 |
| https://git.kernel.org/stable/c/b4f82f9ed43aefa79bec2504ae8c29be0c0f5d1d |
