CVE-2025-38473
Last modified
CVE-2025-38473 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix null-ptr-deref in l2cap_sock_resume_cb() syzbot reported null-ptr-deref in l2cap_sock_resume_cb(). [0] l2cap_sock_resume_cb() has a similar problem that was fixed by commit 1bff51ea59a9 ("Bluetooth: fix use-after-free error in lock_sock_nested()"). Since both l2cap_sock_kill() and l2cap_sock_resume_cb() are executed under l2cap_sock_resume_cb(), we can avoid the issue simply by checking if chan->data is NULL. Let's not access to the killed socket in l2cap_sock_resume_cb(). [0]: BUG: KASAN: null-ptr-deref in instrument_atomic_write include/linux/instrumented.h:82 [inline] BUG: KASAN: null-ptr-deref in clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] BUG: KASAN: null-ptr-deref in l2cap_sock_resume_cb+0xb4/0x17c net/bluetooth/l2cap_sock.c:1711 Write of size 8 at addr 0000000000000570 by task kworker/u9:0/52 CPU: 1 UID: 0 PID: 52 Comm: kworker/u9:0 Not tainted 6.16.0-rc4-syzkaller-g7482bb149b9f #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: hci0 hci_rx_work Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:501 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_report+0x58/0x84 mm/kasan/report.c:524 kasan_report+0xb0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:189 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37 instrument_atomic_write include/linux/instrumented.h:82 [inline] clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] l2cap_sock_resume_cb+0xb4/0x17c net/bluetooth/l2cap_sock.c:1711 l2cap_security_cfm+0x524/0xea0 net/bluetooth/l2cap_core.c:7357 hci_auth_cfm include/net/bluetooth/hci_core.h:2092 [inline] hci_auth_complete_evt+0x2e8/0xa4c net/bluetooth/hci_event.c:3514 hci_event_func net/bluetooth/hci_event.c:7511 [inline] hci_event_packet+0x650/0xe9c net/bluetooth/hci_event.c:7565 hci_rx_work+0x320/0xb18 net/bluetooth/hci_core.c:4070 process_one_work+0x7e8/0x155c kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3402 kthread+0x5fc/0x75c kernel/kthread.c:464 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847. EPSS estimates a 0.15% chance of exploitation in the next 30 days.
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix null-ptr-deref in l2cap_sock_resume_cb() syzbot reported null-ptr-deref in l2cap_sock_resume_cb(). [0] l2cap_sock_resume_cb() has a similar problem that was fixed by commit 1bff51ea59a9 ("Bluetooth: fix use-after-free error in lock_sock_nested()"). Since both l2cap_sock_kill() and l2cap_sock_resume_cb() are executed under l2cap_sock_resume_cb(), we can avoid the issue simply by checking if chan->data is NULL. Let's not access to the killed socket in l2cap_sock_resume_cb(). [0]: BUG: KASAN: null-ptr-deref in instrument_atomic_write include/linux/instrumented.h:82 [inline] BUG: KASAN: null-ptr-deref in clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] BUG: KASAN: null-ptr-deref in l2cap_sock_resume_cb+0xb4/0x17c net/bluetooth/l2cap_sock.c:1711 Write of size 8 at addr 0000000000000570 by task kworker/u9:0/52 CPU: 1 UID: 0 PID: 52 Comm: kworker/u9:0 Not tainted 6.16.0-rc4-syzkaller-g7482bb149b9f #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: hci0 hci_rx_work Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:501 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_report+0x58/0x84 mm/kasan/report.c:524 kasan_report+0xb0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:189 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37 instrument_atomic_write include/linux/instrumented.h:82 [inline] clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] l2cap_sock_resume_cb+0xb4/0x17c net/bluetooth/l2cap_sock.c:1711 l2cap_security_cfm+0x524/0xea0 net/bluetooth/l2cap_core.c:7357 hci_auth_cfm include/net/bluetooth/hci_core.h:2092 [inline] hci_auth_complete_evt+0x2e8/0xa4c net/bluetooth/hci_event.c:3514 hci_event_func net/bluetooth/hci_event.c:7511 [inline] hci_event_packet+0x650/0xe9c net/bluetooth/hci_event.c:7565 hci_rx_work+0x320/0xb18 net/bluetooth/hci_core.c:4070 process_one_work+0x7e8/0x155c kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3402 kthread+0x5fc/0x75c kernel/kthread.c:464 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions | Update |
|---|---|---|---|
| Linux | Linux Kernel | >= 3.13, < 5.4.297 | — |
| Linux | Linux Kernel | >= 5.5, < 5.10.241 | — |
| Linux | Linux Kernel | >= 5.11, < 5.15.190 | — |
| Linux | Linux Kernel | >= 5.16, < 6.1.147 | — |
| Linux | Linux Kernel | >= 6.2, < 6.6.100 | — |
| Linux | Linux Kernel | >= 6.7, < 6.12.40 | — |
| Linux | Linux Kernel | >= 6.13, < 6.15.8 | — |
| Linux | Linux Kernel | 6.16 | Rc1 |
| Debian | Debian Linux | 11.0 | — |
References
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlMailing List, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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