Highly exploitable, CVE-2025-38592 poses a critical security risk that could lead to severe breaches.
Status: Analyzed
Last updated: 🕠 26 Nov 2025, 17:59 UTC
Originally published on: 🕔 19 Aug 2025, 17:15 UTC
Time between publication and last update: 99 days
CVSS Release: version 3
nvd@nist.gov
Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
CVE-2025-38592: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_devcd_dump: fix out-of-bounds via dev_coredumpv Currently both dev_coredumpv and skb_put_data in hci_devcd_dump use hdev->dump.head. However, dev_coredumpv can free the buffer. From dev_coredumpm_timeout documentation, which is used by dev_coredumpv: > Creates a new device coredump for the given device. If a previous one hasn't > been read yet, the new coredump is discarded. The data lifetime is determined > by the device coredump framework and when it is no longer needed the @free > function will be called to free the data. If the data has not been read by the userspace yet, dev_coredumpv will discard new buffer, freeing hdev->dump.head. This leads to vmalloc-out-of-bounds error when skb_put_data tries to access hdev->dump.head. A crash report from syzbot illustrates this: ================================================================== BUG: KASAN: vmalloc-out-of-bounds in skb_put_data include/linux/skbuff.h:2752 [inline] BUG: KASAN: vmalloc-out-of-bounds in hci_devcd_dump+0x142/0x240 net/bluetooth/coredump.c:258 Read of size 140 at addr ffffc90004ed5000 by task kworker/u9:2/5844 CPU: 1 UID: 0 PID: 5844 Comm: kworker/u9:2 Not tainted 6.14.0-syzkaller-10892-g4e82c87058f4 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: hci0 hci_devcd_timeout Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105 skb_put_data include/linux/skbuff.h:2752 [inline] hci_devcd_dump+0x142/0x240 net/bluetooth/coredump.c:258 hci_devcd_timeout+0xb5/0x2e0 net/bluetooth/coredump.c:413 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> The buggy address ffffc90004ed5000 belongs to a vmalloc virtual mapping Memory state around the buggy address: ffffc90004ed4f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90004ed4f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >ffffc90004ed5000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc90004ed5080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90004ed5100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== To avoid this issue, reorder dev_coredumpv to be called after skb_put_data that does not free the data.
The exploitability of CVE-2025-38592 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2025-38592 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2025-38592, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2025-38592, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
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