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VulnerabilityPublished Updated

CVE-2025-71109: Linux kernel · MIPS: ftrace: Fix memory corruption when kernel is located beyond 32 bits

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.1 High · fixed in e3e33ac2eb69d595079a1a1e444c2fb98efdd42d : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.1High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in e3e33ac2eb69d595079a1a1e444c2fb98efdd42d, 36dac9a3dda1f2bae343191bc16b910c603cac25, 9cfda98cf02eacfa6b09076e98bd479fd73407c2 +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 14 Jan 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade Linux kernel to e3e33ac2eb69d595079a1a1e444c2fb98efdd42d, 36dac9a3dda1f2bae343191bc16b910c603cac25, 9cfda98cf02eacfa6b09076e98bd479fd73407c2 or 7f39b9d0e86ed6236b9a5fb67616ab1f76c4f150.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ e424054000878d7eb11e44289242886d6e219d22, < e3e33ac2eb69d595079a1a1e444c2fb98efdd42d
Fixed in
  • e3e33ac2eb69d595079a1a1e444c2fb98efdd42d
LinuxLinuxAffected
  • ≥ e424054000878d7eb11e44289242886d6e219d22, < 36dac9a3dda1f2bae343191bc16b910c603cac25
Fixed in
  • 36dac9a3dda1f2bae343191bc16b910c603cac25
LinuxLinuxAffected
  • ≥ e424054000878d7eb11e44289242886d6e219d22, < 9cfda98cf02eacfa6b09076e98bd479fd73407c2
Fixed in
  • 9cfda98cf02eacfa6b09076e98bd479fd73407c2
LinuxLinuxAffected
  • ≥ e424054000878d7eb11e44289242886d6e219d22, < 7f39b9d0e86ed6236b9a5fb67616ab1f76c4f150
Fixed in
  • 7f39b9d0e86ed6236b9a5fb67616ab1f76c4f150
LinuxLinuxAffected
  • =2.6.35
Fixed in–

Description

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.

References

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