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| author |   Andy Lutomirski <luto@kernel.org> | 2015-07-30 14:31:34 -0700 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2015-07-31 13:30:45 +0200 |
| commit | a5b9e5a2f14f25a8dae987494d50ad3aac7366b6 (patch) | |
| tree | 40b3ab61f67d5c4df17e25dea053f3a9aeb6934d /arch/x86/kernel/step.c | |
| parent | selftests/x86, x86/ldt: Add a selftest for modify_ldt() (diff) | |
| download | linux-dev-a5b9e5a2f14f25a8dae987494d50ad3aac7366b6.tar.xz linux-dev-a5b9e5a2f14f25a8dae987494d50ad3aac7366b6.zip | |
x86/ldt: Make modify_ldt() optional
The modify_ldt syscall exposes a large attack surface and is
unnecessary for modern userspace. Make it optional.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org <security@kernel.org>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/a605166a771c343fd64802dece77a903507333bd.1438291540.git.luto@kernel.org
[ Made MATH_EMULATION dependent on MODIFY_LDT_SYSCALL. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/step.c')
| -rw-r--r-- | arch/x86/kernel/step.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c index 6273324186ac..fd88e152d584 100644 --- a/arch/x86/kernel/step.c +++ b/arch/x86/kernel/step.c @@ -18,6 +18,7 @@ unsigned long convert_ip_to_linear(struct task_struct *child, struct pt_regs *re return addr; } +#ifdef CONFIG_MODIFY_LDT_SYSCALL /* * We'll assume that the code segments in the GDT * are all zero-based. That is largely true: the @@ -45,6 +46,7 @@ unsigned long convert_ip_to_linear(struct task_struct *child, struct pt_regs *re } mutex_unlock(&child->mm->context.lock); } +#endif return addr; } |