diff --git a/Kernel/Syscalls/mmap.cpp b/Kernel/Syscalls/mmap.cpp index 8eeee8be33..a18dc1d4d5 100644 --- a/Kernel/Syscalls/mmap.cpp +++ b/Kernel/Syscalls/mmap.cpp @@ -267,6 +267,23 @@ void* Process::sys$mmap(Userspace user_params) return region->vaddr().as_ptr(); } +static KResultOr expand_range_to_page_boundaries(FlatPtr address, size_t size) +{ + if (page_round_up_would_wrap(size)) + return EINVAL; + + if ((address + size) < address) + return EINVAL; + + if (page_round_up_would_wrap(address + size)) + return EINVAL; + + auto base = VirtualAddress { address }.page_base(); + auto end = page_round_up(address + size); + + return Range { base, end - base.get() }; +} + int Process::sys$mprotect(void* addr, size_t size, int prot) { REQUIRE_PROMISE(stdio); @@ -275,11 +292,11 @@ int Process::sys$mprotect(void* addr, size_t size, int prot) REQUIRE_PROMISE(prot_exec); } - if (page_round_up_would_wrap(size)) - return -EINVAL; - - Range range_to_mprotect = { VirtualAddress((FlatPtr)addr & PAGE_MASK), page_round_up(size) }; + auto range_or_error = expand_range_to_page_boundaries((FlatPtr)addr, size); + if (range_or_error.is_error()) + return range_or_error.error(); + auto range_to_mprotect = range_or_error.value(); if (!range_to_mprotect.size()) return -EINVAL; @@ -349,10 +366,11 @@ int Process::sys$madvise(void* address, size_t size, int advice) { REQUIRE_PROMISE(stdio); - if (page_round_up_would_wrap(size)) - return -EINVAL; + auto range_or_error = expand_range_to_page_boundaries((FlatPtr)address, size); + if (range_or_error.is_error()) + return range_or_error.error(); - Range range_to_madvise { VirtualAddress((FlatPtr)address & PAGE_MASK), page_round_up(size) }; + auto range_to_madvise = range_or_error.value(); if (!range_to_madvise.size()) return -EINVAL; @@ -408,7 +426,13 @@ int Process::sys$set_mmap_name(Userspaceis_mmap()) @@ -424,10 +448,11 @@ int Process::sys$munmap(void* addr, size_t size) if (!size) return -EINVAL; - if (page_round_up_would_wrap(size)) - return -EINVAL; + auto range_or_error = expand_range_to_page_boundaries((FlatPtr)addr, size); + if (range_or_error.is_error()) + return range_or_error.error(); - Range range_to_unmap { VirtualAddress(addr), page_round_up(size) }; + auto range_to_unmap = range_or_error.value(); if (!is_user_range(range_to_unmap)) return -EFAULT; @@ -473,13 +498,13 @@ void* Process::sys$mremap(Userspace user_param if (!copy_from_user(¶ms, user_params)) return (void*)-EFAULT; - if (page_round_up_would_wrap(params.old_size)) - return (void*)-EINVAL; + auto range_or_error = expand_range_to_page_boundaries((FlatPtr)params.old_address, params.old_size); + if (range_or_error.is_error()) + return (void*)range_or_error.error().error(); - auto old_address = page_round_down(params.old_address); - auto old_size = page_round_up(params.old_size); + auto old_range = range_or_error.value(); - auto* old_region = space().find_region_from_range(Range { VirtualAddress { old_address }, old_size }); + auto* old_region = space().find_region_from_range(old_range); if (!old_region) return (void*)-EINVAL;