CVE-2025-71109
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.
- CVSS 3.1
- 5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 13% of CVEs (scores of 2026-10-25)
- CWE
- CWE-787
- Published
- Modified
- Record from
- the NVD, synced
Affected
- linux:linux_kernel