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| author | Jean-Baptiste Boric <jblbeurope@gmail.com> | 2021-03-07 12:36:16 +0100 |
|---|---|---|
| committer | Andreas Kling <kling@serenityos.org> | 2021-03-07 14:05:17 +0100 |
| commit | 32e1354b9b0050dd2920c8506cef2841789e14df (patch) | |
| tree | 978d28e415464ac36d3b991f3d1a0d011fe54b9e /Kernel/Arch | |
| parent | a6f957a36b6b7a51225c0ea7f9e2e22678f3ed31 (diff) | |
| download | serenity-32e1354b9b0050dd2920c8506cef2841789e14df.zip | |
Kernel: Fix unaligned read inside map_ebda()
Diffstat (limited to 'Kernel/Arch')
| -rw-r--r-- | Kernel/Arch/PC/BIOS.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/Kernel/Arch/PC/BIOS.cpp b/Kernel/Arch/PC/BIOS.cpp index 009df2df3f..1214ba80ed 100644 --- a/Kernel/Arch/PC/BIOS.cpp +++ b/Kernel/Arch/PC/BIOS.cpp @@ -43,10 +43,11 @@ MappedROM map_bios() MappedROM map_ebda() { auto ebda_segment_ptr = map_typed<u16>(PhysicalAddress(0x40e)); - auto ebda_length_ptr = map_typed<u16>(PhysicalAddress(0x413)); + auto ebda_length_ptr_b0 = map_typed<u8>(PhysicalAddress(0x413)); + auto ebda_length_ptr_b1 = map_typed<u8>(PhysicalAddress(0x414)); PhysicalAddress ebda_paddr(*ebda_segment_ptr << 4); - size_t ebda_size = *ebda_length_ptr; + size_t ebda_size = (*ebda_length_ptr_b1 << 8) | *ebda_length_ptr_b0; MappedROM mapping; mapping.region = MM.allocate_kernel_region(ebda_paddr.page_base(), page_round_up(ebda_size), {}, Region::Access::Read); |