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| author | Catalin Marinas <catalin.marinas@arm.com> | 2025-02-20 15:58:01 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-03-07 16:56:28 +0100 |
| commit | a27c597f262ddf2356a9cfb1df28fd2588d6ba76 (patch) | |
| tree | 6dc0a73f60091cdc56425f7768f38b4d626b18c9 /arch | |
| parent | 3a83585836269d5109d84a49d4e5b484e54cc6d1 (diff) | |
| download | linux-a27c597f262ddf2356a9cfb1df28fd2588d6ba76.tar.gz linux-a27c597f262ddf2356a9cfb1df28fd2588d6ba76.tar.bz2 linux-a27c597f262ddf2356a9cfb1df28fd2588d6ba76.zip | |
arm64: mte: Do not allow PROT_MTE on MAP_HUGETLB user mappings
PROT_MTE (memory tagging extensions) is not supported on all user mmap()
types for various reasons (memory attributes, backing storage, CoW
handling). The arm64 arch_validate_flags() function checks whether the
VM_MTE_ALLOWED flag has been set for a vma during mmap(), usually by
arch_calc_vm_flag_bits().
Linux prior to 6.13 does not support PROT_MTE hugetlb mappings. This was
added by commit 25c17c4b55de ("hugetlb: arm64: add mte support").
However, earlier kernels inadvertently set VM_MTE_ALLOWED on
(MAP_ANONYMOUS | MAP_HUGETLB) mappings by only checking for
MAP_ANONYMOUS.
Explicitly check MAP_HUGETLB in arch_calc_vm_flag_bits() and avoid
setting VM_MTE_ALLOWED for such mappings.
Fixes: 9f3419315f3c ("arm64: mte: Add PROT_MTE support to mmap() and mprotect()")
Cc: <stable@vger.kernel.org> # 5.10.x-6.12.x
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/mman.h | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h index ef35c52aabd6..101771c60d80 100644 --- a/arch/arm64/include/asm/mman.h +++ b/arch/arm64/include/asm/mman.h @@ -31,9 +31,12 @@ static inline unsigned long arch_calc_vm_flag_bits(struct file *file, * backed by tags-capable memory. The vm_flags may be overridden by a * filesystem supporting MTE (RAM-based). */ - if (system_supports_mte() && - ((flags & MAP_ANONYMOUS) || shmem_file(file))) - return VM_MTE_ALLOWED; + if (system_supports_mte()) { + if ((flags & MAP_ANONYMOUS) && !(flags & MAP_HUGETLB)) + return VM_MTE_ALLOWED; + if (shmem_file(file)) + return VM_MTE_ALLOWED; + } return 0; } |