Microsoft security update for CVE-2025-39683
🔗 CVE IDs covered (1)
📋 Microsoft's advisory
EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-39683. This page also shows what EchelonGraph holds for CVE-2025-39683, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.
🎯 Affected products3
- azl3 kernel 6.6.96.2-1 on Azure Linux 3.0
- azl3 kernel 6.6.96.2-2 on Azure Linux 3.0
- cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0
✅ Updates Microsoft lists: 2 updates
2 rows: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.
| KB article | Update | Fixed build |
|---|---|---|
| — | Security Update | 5.15.200.1-1 |
| — | Security Update | 6.6.104.2-1 |
🧭 EchelonGraph on CVE-2025-39683
- EchelonGraph score
- 7.1 HIGH
- CISA KEV
- Not listed
- Fix status
- A fix is available — apply it.
Description from the CVE record (CVE.org), as published by its numbering authority
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.
Published by kernel.org, the CVE Numbering Authority that assigned CVE-2025-39683, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).