| Message ID | 20210521221211.29077-31-yu-cheng.yu@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Control-flow Enforcement: Shadow Stack | expand |
On Fri, May 21, 2021 at 03:12:10PM -0700, Yu-cheng Yu wrote: > When newer VM flags are being created, such as VM_MTE, it becomes necessary > for mmap/mprotect to verify if certain flags are being applied to an > anonymous VMA. > > To solve this, one approach is adding a VM flag to track that MAP_ANONYMOUS > is specified [1], and then using the flag in arch_validate_flags(). > > Another approach is passing the VMA to arch_validate_flags(), and check > vma_is_anonymous(). > > To prepare the introduction of PROT_SHADOW_STACK, which creates a shadow > stack mapping and can be applied only to an anonymous VMA, update > arch_validate_flags() to pass in the VMA. > > [1] commit 9f3419315f3c ("arm64: mte: Add PROT_MTE support to mmap() and mprotect()"), > > Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> > Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Kees Cook <keescook@chromium.org> > Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> > Cc: Will Deacon <will@kernel.org> For arm64: Acked-by: Catalin Marinas <catalin.marinas@arm.com>
On 5/25/2021 4:00 AM, Catalin Marinas wrote: > On Fri, May 21, 2021 at 03:12:10PM -0700, Yu-cheng Yu wrote: >> When newer VM flags are being created, such as VM_MTE, it becomes necessary >> for mmap/mprotect to verify if certain flags are being applied to an >> anonymous VMA. >> >> To solve this, one approach is adding a VM flag to track that MAP_ANONYMOUS >> is specified [1], and then using the flag in arch_validate_flags(). >> >> Another approach is passing the VMA to arch_validate_flags(), and check >> vma_is_anonymous(). >> >> To prepare the introduction of PROT_SHADOW_STACK, which creates a shadow >> stack mapping and can be applied only to an anonymous VMA, update >> arch_validate_flags() to pass in the VMA. >> >> [1] commit 9f3419315f3c ("arm64: mte: Add PROT_MTE support to mmap() and mprotect()"), >> >> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> >> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> >> Cc: Catalin Marinas <catalin.marinas@arm.com> >> Cc: Kees Cook <keescook@chromium.org> >> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> >> Cc: Will Deacon <will@kernel.org> > > For arm64: > > Acked-by: Catalin Marinas <catalin.marinas@arm.com> > Thanks!
diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h index e3e28f7daf62..7c45e7578f78 100644 --- a/arch/arm64/include/asm/mman.h +++ b/arch/arm64/include/asm/mman.h @@ -74,7 +74,7 @@ static inline bool arch_validate_prot(unsigned long prot, } #define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr) -static inline bool arch_validate_flags(unsigned long vm_flags) +static inline bool arch_validate_flags(struct vm_area_struct *vma, unsigned long vm_flags) { if (!system_supports_mte()) return true; @@ -82,6 +82,6 @@ static inline bool arch_validate_flags(unsigned long vm_flags) /* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */ return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED); } -#define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags) +#define arch_validate_flags(vma, vm_flags) arch_validate_flags(vma, vm_flags) #endif /* ! __ASM_MMAN_H__ */ diff --git a/arch/sparc/include/asm/mman.h b/arch/sparc/include/asm/mman.h index 274217e7ed70..0ec4975f167d 100644 --- a/arch/sparc/include/asm/mman.h +++ b/arch/sparc/include/asm/mman.h @@ -60,11 +60,11 @@ static inline int sparc_validate_prot(unsigned long prot, unsigned long addr) return 1; } -#define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags) +#define arch_validate_flags(vma, vm_flags) arch_validate_flags(vma, vm_flags) /* arch_validate_flags() - Ensure combination of flags is valid for a * VMA. */ -static inline bool arch_validate_flags(unsigned long vm_flags) +static inline bool arch_validate_flags(struct vm_area_struct *vma, unsigned long vm_flags) { /* If ADI is being enabled on this VMA, check for ADI * capability on the platform and ensure VMA is suitable diff --git a/include/linux/mman.h b/include/linux/mman.h index 629cefc4ecba..41d6fbf4e7d9 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -114,7 +114,7 @@ static inline bool arch_validate_prot(unsigned long prot, unsigned long addr) * * Returns true if the VM_* flags are valid. */ -static inline bool arch_validate_flags(unsigned long flags) +static inline bool arch_validate_flags(struct vm_area_struct *vma, unsigned long flags) { return true; } diff --git a/mm/mmap.c b/mm/mmap.c index a99b01877c45..352ad2762a6b 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1856,7 +1856,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, } /* Allow architectures to sanity-check the vm_flags */ - if (!arch_validate_flags(vma->vm_flags)) { + if (!arch_validate_flags(vma, vma->vm_flags)) { error = -EINVAL; if (file) goto unmap_and_free_vma; diff --git a/mm/mprotect.c b/mm/mprotect.c index 40428e8536bb..c28f9b1c9069 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -611,7 +611,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len, } /* Allow architectures to sanity-check the new flags */ - if (!arch_validate_flags(newflags)) { + if (!arch_validate_flags(vma, newflags)) { error = -EINVAL; goto out; }
When newer VM flags are being created, such as VM_MTE, it becomes necessary for mmap/mprotect to verify if certain flags are being applied to an anonymous VMA. To solve this, one approach is adding a VM flag to track that MAP_ANONYMOUS is specified [1], and then using the flag in arch_validate_flags(). Another approach is passing the VMA to arch_validate_flags(), and check vma_is_anonymous(). To prepare the introduction of PROT_SHADOW_STACK, which creates a shadow stack mapping and can be applied only to an anonymous VMA, update arch_validate_flags() to pass in the VMA. [1] commit 9f3419315f3c ("arm64: mte: Add PROT_MTE support to mmap() and mprotect()"), Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Kees Cook <keescook@chromium.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> --- arch/arm64/include/asm/mman.h | 4 ++-- arch/sparc/include/asm/mman.h | 4 ++-- include/linux/mman.h | 2 +- mm/mmap.c | 2 +- mm/mprotect.c | 2 +- 5 files changed, 7 insertions(+), 7 deletions(-)