MIPS: ftrace: Fix memory corruption when kernel is located beyond 32 bits
CVE-2025-71109 · published 14 Jan 2026
How serious is it
- Severity: high, CVSS score 7.1 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2025-71109?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: e424054000878d7eb11e44289242886d6e219d22 to < 9cfda98cf02eacfa6b09076e98bd479fd73407c2, e424054000878d7eb11e44289242886d6e219d22 to < e3e33ac2eb69d595079a1a1e444c2fb98efdd42d, e424054000878d7eb11e44289242886d6e219d22 to < 7f39b9d0e86ed6236b9a5fb67616ab1f76c4f150, e424054000878d7eb11e44289242886d6e219d22 to < 36dac9a3dda1f2bae343191bc16b910c603cac25
- Linux Linux: 2.6.35
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
MIPS: ftrace: Fix memory corruption when kernel is located beyond 32 bits
Since commit e424054000878 ("MIPS: Tracing: Reduce the overhead of
dynamic Function Tracer"), the macro UASM_i_LA_mostly has been used,
and this macro can generate more than 2 instructions. At the same
time, the code in ftrace assumes that no more than 2 instructions can
be generated, which is why it stores them in an int[2] array. However,
as previously noted, the macro UASM_i_LA_mostly (and now UASM_i_LA)
causes a buffer overflow when _mcount is beyond 32 bits. This leads to
corruption of the variables located in the __read_mostly section.
This corruption was observed because the variable
__cpu_primary_thread_mask was corrupted, causing a hang very early
during boot.
This fix prevents the corruption by avoiding the generation of
instructions if they could exceed 2 instructions in
length. Fortunately, insn_la_mcount is only used if the instrumented
code is located outside the kernel code section, so dynamic ftrace can
still be used, albeit in a more limited scope. This is still
preferable to corrupting memory and/or crashing the kernel.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/9cfda98cf02eacfa6b09076e98bd479fd73407c2
- git.kernel.org/stable/c/e3e33ac2eb69d595079a1a1e444c2fb98efdd42d
- git.kernel.org/stable/c/7f39b9d0e86ed6236b9a5fb67616ab1f76c4f150
- git.kernel.org/stable/c/36dac9a3dda1f2bae343191bc16b910c603cac25
Merged from CVE List. Last updated 25 Oct 2026. All vulnerabilities · RSS · JSON