CVE-2025-39683
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-09-05

Last updated on: 2025-11-03

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: tracing: Limit access to parser->buffer when trace_get_user failed When the length of the string written to set_ftrace_filter exceeds FTRACE_BUFF_MAX, the following KASAN alarm will be triggered: BUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0 Read of size 1 at addr ffff0000d00bd5ba by task ash/165 CPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x34/0x50 (C) dump_stack_lvl+0xa0/0x158 print_address_description.constprop.0+0x88/0x398 print_report+0xb0/0x280 kasan_report+0xa4/0xf0 __asan_report_load1_noabort+0x20/0x30 strsep+0x18c/0x1b0 ftrace_process_regex.isra.0+0x100/0x2d8 ftrace_regex_release+0x484/0x618 __fput+0x364/0xa58 ____fput+0x28/0x40 task_work_run+0x154/0x278 do_notify_resume+0x1f0/0x220 el0_svc+0xec/0xf0 el0t_64_sync_handler+0xa0/0xe8 el0t_64_sync+0x1ac/0x1b0 The reason is that trace_get_user will fail when processing a string longer than FTRACE_BUFF_MAX, but not set the end of parser->buffer to 0. Then an OOB access will be triggered in ftrace_regex_release-> ftrace_process_regex->strsep->strpbrk. We can solve this problem by limiting access to parser->buffer when trace_get_user failed.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2025-09-05
Last Modified
2025-11-03
Generated
2026-05-07
AI Q&A
2025-09-05
EPSS Evaluated
2026-05-05
NVD
CVE-2025-39683
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
linux linux_kernel 5.10.244
linux linux_kernel 6.1.153
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability occurs in the Linux kernel's tracing subsystem. When a string longer than the maximum allowed length (FTRACE_BUFF_MAX) is written to set_ftrace_filter, a function called trace_get_user fails but does not properly terminate the buffer. This leads to an out-of-bounds (OOB) memory access when the kernel later processes this buffer, causing a KASAN (Kernel Address Sanitizer) alarm. Essentially, the kernel reads beyond the allocated memory, which can cause instability or crashes.


How can this vulnerability impact me? :

This vulnerability can cause the Linux kernel to crash or behave unpredictably due to out-of-bounds memory access. This can lead to denial of service or potentially allow an attacker to exploit the kernel's memory corruption to execute arbitrary code or escalate privileges, depending on the context and further exploitation.


Ask Our AI Assistant
Need more information? Ask your question to get an AI reply (Powered by our expertise)
0/70
EPSS Chart