{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-71109", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:30:19.652Z", "datePublished": "2026-01-14T15:05:57.236Z", "dateUpdated": "2026-08-05T12:12:07.933Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:12:07.933Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nMIPS: ftrace: Fix memory corruption when kernel is located beyond 32 bits\n\nSince commit e424054000878 (\"MIPS: Tracing: Reduce the overhead of\ndynamic Function Tracer\"), the macro UASM_i_LA_mostly has been used,\nand this macro can generate more than 2 instructions. At the same\ntime, the code in ftrace assumes that no more than 2 instructions can\nbe generated, which is why it stores them in an int[2] array. However,\nas previously noted, the macro UASM_i_LA_mostly (and now UASM_i_LA)\ncauses a buffer overflow when _mcount is beyond 32 bits. This leads to\ncorruption of the variables located in the __read_mostly section.\n\nThis corruption was observed because the variable\n__cpu_primary_thread_mask was corrupted, causing a hang very early\nduring boot.\n\nThis fix prevents the corruption by avoiding the generation of\ninstructions if they could exceed 2 instructions in\nlength. Fortunately, insn_la_mcount is only used if the instrumented\ncode is located outside the kernel code section, so dynamic ftrace can\nstill be used, albeit in a more limited scope. This is still\npreferable to corrupting memory and/or crashing the kernel." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The overflow occurs only during local MIPS kernel boot-time ftrace initialization; no network, radio, or device-input handler reaches it.\nAC:L - On an affected build with dynamic ftrace and _mcount beyond 32-bit compatibility space, the overflow occurs deterministically during every boot without a race or heap grooming.\nPR:L - No ftrace or tracefs permission check gates the vulnerable boot path, which executes before userspace; conservatively, ordinary local access is sufficient rather than requiring real root.\nUI:N - The vulnerable instruction generation happens automatically during normal kernel boot without requiring a victim to enable tracing, mount tracefs, or open a file.\nS:U - The corruption affects the same kernel security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:N - The bounded overwrite emits deterministic MIPS instruction words and provides no identified memory-read primitive or path for returning corrupted memory to an attacker.\nI:H - Up to several instructions are written beyond the two-word array into adjacent kernel globals, constituting an out-of-bounds kernel write capable of corrupting security-critical state.\nA:H - Corruption of __cpu_primary_thread_mask was observed to hang the kernel very early during boot, preventing affected servers, embedded controllers, or automotive systems from becoming operational." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/mips/kernel/ftrace.c" ], "versions": [ { "version": "e424054000878d7eb11e44289242886d6e219d22", "lessThan": "e3e33ac2eb69d595079a1a1e444c2fb98efdd42d", "status": "affected", "versionType": "git" }, { "version": "e424054000878d7eb11e44289242886d6e219d22", "lessThan": "7f39b9d0e86ed6236b9a5fb67616ab1f76c4f150", "status": "affected", "versionType": "git" }, { "version": "e424054000878d7eb11e44289242886d6e219d22", "lessThan": "36dac9a3dda1f2bae343191bc16b910c603cac25", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/mips/kernel/ftrace.c" ], "versions": [ { "version": "2.6.35", "status": "affected" }, { "version": "0", "lessThan": "2.6.35", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.64", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.3", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "6.12.64" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "6.18.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "6.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e3e33ac2eb69d595079a1a1e444c2fb98efdd42d" }, { "url": "https://git.kernel.org/stable/c/7f39b9d0e86ed6236b9a5fb67616ab1f76c4f150" }, { "url": "https://git.kernel.org/stable/c/36dac9a3dda1f2bae343191bc16b910c603cac25" } ], "title": "MIPS: ftrace: Fix memory corruption when kernel is located beyond 32 bits", "x_generator": { "engine": "bippy-1.2.0" } } } }