-
CVE-2025-38435
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: vector: Fix context save/restore with xtheadvector
Previously only v0-v7 were correctly saved/restored,
and the context of v8-v31 are damanged.
Correctly save/restore v8-v31 to avoid breaking userspace.
-
CVE-2025-38435
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: vector: Fix context save/restore with xtheadvector
Previously only v0-v7 were correctly saved/restored,
and the context of v8-v31 are damanged.
Correctly save/restore v8-v31 to avoid breaking userspace.
-
CVE-2025-38435
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: vector: Fix context save/restore with xtheadvector
Previously only v0-v7 were correctly saved/restored,
and the context of v8-v31 are damanged.
Correctly save/restore v8-v31 to avoid breaking userspace.
-
CVE-2025-38435
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: vector: Fix context save/restore with xtheadvector
Previously only v0-v7 were correctly saved/restored,
and the context of v8-v31 are damanged.
Correctly save/restore v8-v31 to avoid breaking userspace.
-
CVE-2025-38435
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: vector: Fix context save/restore with xtheadvector
Previously only v0-v7 were correctly saved/restored,
and the context of v8-v31 are damanged.
Correctly save/restore v8-v31 to avoid breaking userspace.
-
CVE-2025-38435
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: vector: Fix context save/restore with xtheadvector
Previously only v0-v7 were correctly saved/restored,
and the context of v8-v31 are damanged.
Correctly save/restore v8-v31 to avoid breaking userspace.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38434
•
published on July 25, 2025
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.
-
CVE-2025-38433
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: fix runtime constant support for nommu kernels
the `__runtime_fixup_32` function does not handle the case where `val` is
zero correctly (as might occur when patching a nommu kernel and referring
to a physical address below the 4GiB boundary whose upper 32 bits are all
zero) because nothing in the existing logic prevents the code from taking
the `else` branch of both nop-checks and emitting two `nop` instructions.
This leaves random garbage in the register that is supposed to receive the
upper 32 bits of the pointer instead of zero that when combined with the
value for the lower 32 bits yields an invalid pointer and causes a kernel
panic when that pointer is eventually accessed.
The author clearly considered the fact that if the `lui` is converted into
a `nop` that the second instruction needs to be adjusted to become an `li`
instead of an `addi`, hence introducing the `addi_insn_mask` variable, but
didn't follow that logic through fully to the case where the `else` branch
executes. To fix it just adjust the logic to ensure that the second `else`
branch is not taken if the first instruction will be patched to a `nop`.
-
CVE-2025-38433
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: fix runtime constant support for nommu kernels
the `__runtime_fixup_32` function does not handle the case where `val` is
zero correctly (as might occur when patching a nommu kernel and referring
to a physical address below the 4GiB boundary whose upper 32 bits are all
zero) because nothing in the existing logic prevents the code from taking
the `else` branch of both nop-checks and emitting two `nop` instructions.
This leaves random garbage in the register that is supposed to receive the
upper 32 bits of the pointer instead of zero that when combined with the
value for the lower 32 bits yields an invalid pointer and causes a kernel
panic when that pointer is eventually accessed.
The author clearly considered the fact that if the `lui` is converted into
a `nop` that the second instruction needs to be adjusted to become an `li`
instead of an `addi`, hence introducing the `addi_insn_mask` variable, but
didn't follow that logic through fully to the case where the `else` branch
executes. To fix it just adjust the logic to ensure that the second `else`
branch is not taken if the first instruction will be patched to a `nop`.
-
CVE-2025-38433
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: fix runtime constant support for nommu kernels
the `__runtime_fixup_32` function does not handle the case where `val` is
zero correctly (as might occur when patching a nommu kernel and referring
to a physical address below the 4GiB boundary whose upper 32 bits are all
zero) because nothing in the existing logic prevents the code from taking
the `else` branch of both nop-checks and emitting two `nop` instructions.
This leaves random garbage in the register that is supposed to receive the
upper 32 bits of the pointer instead of zero that when combined with the
value for the lower 32 bits yields an invalid pointer and causes a kernel
panic when that pointer is eventually accessed.
The author clearly considered the fact that if the `lui` is converted into
a `nop` that the second instruction needs to be adjusted to become an `li`
instead of an `addi`, hence introducing the `addi_insn_mask` variable, but
didn't follow that logic through fully to the case where the `else` branch
executes. To fix it just adjust the logic to ensure that the second `else`
branch is not taken if the first instruction will be patched to a `nop`.
-
CVE-2025-38433
•
published on July 25, 2025
In the Linux kernel, the following vulnerability has been resolved:
riscv: fix runtime constant support for nommu kernels
the `__runtime_fixup_32` function does not handle the case where `val` is
zero correctly (as might occur when patching a nommu kernel and referring
to a physical address below the 4GiB boundary whose upper 32 bits are all
zero) because nothing in the existing logic prevents the code from taking
the `else` branch of both nop-checks and emitting two `nop` instructions.
This leaves random garbage in the register that is supposed to receive the
upper 32 bits of the pointer instead of zero that when combined with the
value for the lower 32 bits yields an invalid pointer and causes a kernel
panic when that pointer is eventually accessed.
The author clearly considered the fact that if the `lui` is converted into
a `nop` that the second instruction needs to be adjusted to become an `li`
instead of an `addi`, hence introducing the `addi_insn_mask` variable, but
didn't follow that logic through fully to the case where the `else` branch
executes. To fix it just adjust the logic to ensure that the second `else`
branch is not taken if the first instruction will be patched to a `nop`.