Messages in this thread Patch in this message | | | Date | Fri, 12 Jul 2013 11:30:14 -0700 | From | Kees Cook <> | Subject | [PATCH] x86: make sure IDT is page aligned |
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Since the IDT is referenced from a fixmap, make sure it is page aligned. This avoids the risk of it ever being moved in the bss and having the fixmap fail.
Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: PaX Team <pageexec@freemail.hu> Cc: stable@vger.kernel.org --- arch/x86/kernel/head_32.S | 2 +- arch/x86/kernel/head_64.S | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index e65ddc6..3526dd1 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -734,7 +734,7 @@ boot_gdt_descr: .word __BOOT_DS+7 .long boot_gdt - __PAGE_OFFSET - .word 0 # 32-bit align idt_desc.address + .word PAGE_SIZE # page align idt_desc.address idt_descr: .word IDT_ENTRIES*8-1 # idt contains 256 entries .long idt_table diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 5e4d8a8..77e6d3e 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -513,7 +513,7 @@ ENTRY(phys_base) #include "../../x86/xen/xen-head.S" .section .bss, "aw", @nobits - .align L1_CACHE_BYTES + .align PAGE_SIZE ENTRY(idt_table) .skip IDT_ENTRIES * 16 -- 1.7.9.5
-- Kees Cook Chrome OS Security
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