Answer in brief
CVE-2025-38434 records a Unknown severity vulnerability in Revert "riscv: Define TASK_SIZE_MAX for __access_ok()". The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=ad5643cf2f699989daa85d909403febd6712fccb <fe30c30bf3bb68d4a4d8c7c814769857b5c973e6 || >=ad5643cf2f699989daa85d909403febd6712fccb <f8b1898748dfeb4f9b67b6a6d661f354b9de3523 || >=ad5643cf2f699989daa85d909403febd6712fccb <890ba5be6335dbbbc99af14ea007befb5f83f174 | fe30c30bf3bb68d4a4d8c7c814769857b5c973e6, f8b1898748dfeb4f9b67b6a6d661f354b9de3523, 890ba5be6335dbbbc99af14ea007befb5f83f174 |
| Linux/Linuxgeneric | 6.10 | Not reported |
Published upstream
Jul 25, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: Revert "riscv: Define TASK_SIZE_MAX for __access_ok()" This reverts commit ad5643cf2f69 ("riscv: Define TASK_SIZE_MAX for __access_ok()"). This commit changes TASK_SIZE_MAX to be LONG_MAX to optimize access_ok(), because the previous TASK_SIZE_MAX (default to TASK_SIZE) requires some computation. The reasoning was that all user addresses are less than LONG_MAX, and all kernel addresses are greater than LONG_MAX. Therefore access_ok() can filter kernel addresses. Addresses between TASK_SIZE and LONG_MAX are not valid user addresses, but access_ok() let them pass. That was thought to be okay, because they are not valid addresses at hardware level. Unfortunately, one case is missed: get_user_pages_fast() happily accepts addresses between TASK_SIZE and LONG_MAX. futex(), for instance, uses get_user_pages_fast(). This causes the problem reported by Robert [1]. Therefore, revert this commit. TASK_SIZE_MAX is changed to the default: TASK_SIZE. This unfortunately reduces performance, because TASK_SIZE is more expensive to compute compared to LONG_MAX. But correctness first, we can think about optimization later, if required.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2025-38434 records a Unknown severity vulnerability in Revert "riscv: Define TASK_SIZE_MAX for __access_ok()". The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=ad5643cf2f699989daa85d909403febd6712fccb <fe30c30bf3bb68d4a4d8c7c814769857b5c973e6 || >=ad5643cf2f699989daa85d909403febd6712fccb <f8b1898748dfeb4f9b67b6a6d661f354b9de3523 || >=ad5643cf2f699989daa85d909403febd6712fccb <890ba5be6335dbbbc99af14ea007befb5f83f174 | fe30c30bf3bb68d4a4d8c7c814769857b5c973e6, f8b1898748dfeb4f9b67b6a6d661f354b9de3523, 890ba5be6335dbbbc99af14ea007befb5f83f174 |
| Linux/Linuxgeneric | 6.10 | Not reported |
Published upstream
Jul 25, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: Revert "riscv: Define TASK_SIZE_MAX for __access_ok()" This reverts commit ad5643cf2f69 ("riscv: Define TASK_SIZE_MAX for __access_ok()"). This commit changes TASK_SIZE_MAX to be LONG_MAX to optimize access_ok(), because the previous TASK_SIZE_MAX (default to TASK_SIZE) requires some computation. The reasoning was that all user addresses are less than LONG_MAX, and all kernel addresses are greater than LONG_MAX. Therefore access_ok() can filter kernel addresses. Addresses between TASK_SIZE and LONG_MAX are not valid user addresses, but access_ok() let them pass. That was thought to be okay, because they are not valid addresses at hardware level. Unfortunately, one case is missed: get_user_pages_fast() happily accepts addresses between TASK_SIZE and LONG_MAX. futex(), for instance, uses get_user_pages_fast(). This causes the problem reported by Robert [1]. Therefore, revert this commit. TASK_SIZE_MAX is changed to the default: TASK_SIZE. This unfortunately reduces performance, because TASK_SIZE is more expensive to compute compared to LONG_MAX. But correctness first, we can think about optimization later, if required.
Quoted source text, attributed separately from HOL analysis.