diff options
| author | Andy Lutomirski <luto@MIT.EDU> | 2011-06-05 13:50:23 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-06-06 09:43:14 +0200 |
| commit | 5dfcea629a08b4684a019cd0cb59d0c9129a6c02 (patch) | |
| tree | 0f8c7ae0db1cc4d7bf75dc7dd5612de7c741145c /arch/x86/kernel | |
| parent | bb5fe2f78eadf5a52d8dcbf9a57728fd107af97b (diff) | |
x86-64: Fill unused parts of the vsyscall page with 0xcc
Jumping to 0x00 might do something depending on the following
bytes. Jumping to 0xcc is a trap. So fill the unused parts of
the vsyscall page with 0xcc to make it useless for exploits to
jump there.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/ed54bfcfbe50a9070d20ec1edbe0d149e22a4568.1307292171.git.luto@mit.edu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 4f90082fd64..80174719910 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -166,22 +166,20 @@ SECTIONS __vsyscall_0 = .; . = VSYSCALL_ADDR; - .vsyscall_0 : AT(VLOAD(.vsyscall_0)) { + .vsyscall : AT(VLOAD(.vsyscall)) { *(.vsyscall_0) - } :user - . = ALIGN(L1_CACHE_BYTES); - .vsyscall_fn : AT(VLOAD(.vsyscall_fn)) { + . = ALIGN(L1_CACHE_BYTES); *(.vsyscall_fn) - } - .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) { + . = 1024; *(.vsyscall_1) - } - .vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) { + + . = 2048; *(.vsyscall_2) - } + . = 4096; /* Pad the whole page. */ + } :user =0xcc . = ALIGN(__vsyscall_0 + PAGE_SIZE, PAGE_SIZE); #undef VSYSCALL_ADDR |