mirror of
https://github.com/brain-hackers/linux-brain.git
synced 2024-06-09 23:36:23 +09:00
x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec
commit 304ec1b050
upstream.
Quoting Linus:
I do think that it would be a good idea to very expressly document
the fact that it's not that the user access itself is unsafe. I do
agree that things like "get_user()" want to be protected, but not
because of any direct bugs or problems with get_user() and friends,
but simply because get_user() is an excellent source of a pointer
that is obviously controlled from a potentially attacking user
space. So it's a prime candidate for then finding _subsequent_
accesses that can then be used to perturb the cache.
__uaccess_begin_nospec() covers __get_user() and copy_from_iter() where the
limit check is far away from the user pointer de-reference. In those cases
a barrier_nospec() prevents speculation with a potential pointer to
privileged memory. uaccess_try_nospec covers get_user_try.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727416953.33451.10508284228526170604.stgit@dwillia2-desk3.amr.corp.intel.com
[bwh: Backported to 4.4:
- Convert several more functions to use __uaccess_begin_nospec(), that
are just wrappers in mainline
- Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
557cd0d20e
commit
67e326e034
|
@ -436,7 +436,7 @@ do { \
|
|||
({ \
|
||||
int __gu_err; \
|
||||
unsigned long __gu_val; \
|
||||
__uaccess_begin(); \
|
||||
__uaccess_begin_nospec(); \
|
||||
__get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \
|
||||
__uaccess_end(); \
|
||||
(x) = (__force __typeof__(*(ptr)))__gu_val; \
|
||||
|
@ -546,7 +546,7 @@ struct __large_struct { unsigned long buf[100]; };
|
|||
* get_user_ex(...);
|
||||
* } get_user_catch(err)
|
||||
*/
|
||||
#define get_user_try uaccess_try
|
||||
#define get_user_try uaccess_try_nospec
|
||||
#define get_user_catch(err) uaccess_catch(err)
|
||||
|
||||
#define get_user_ex(x, ptr) do { \
|
||||
|
@ -581,7 +581,7 @@ extern void __cmpxchg_wrong_size(void)
|
|||
__typeof__(ptr) __uval = (uval); \
|
||||
__typeof__(*(ptr)) __old = (old); \
|
||||
__typeof__(*(ptr)) __new = (new); \
|
||||
__uaccess_begin(); \
|
||||
__uaccess_begin_nospec(); \
|
||||
switch (size) { \
|
||||
case 1: \
|
||||
{ \
|
||||
|
|
|
@ -48,25 +48,25 @@ __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
|
|||
|
||||
switch (n) {
|
||||
case 1:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__put_user_size(*(u8 *)from, (u8 __user *)to,
|
||||
1, ret, 1);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 2:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__put_user_size(*(u16 *)from, (u16 __user *)to,
|
||||
2, ret, 2);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 4:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__put_user_size(*(u32 *)from, (u32 __user *)to,
|
||||
4, ret, 4);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 8:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__put_user_size(*(u64 *)from, (u64 __user *)to,
|
||||
8, ret, 8);
|
||||
__uaccess_end();
|
||||
|
@ -111,17 +111,17 @@ __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
|
|||
|
||||
switch (n) {
|
||||
case 1:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_size(*(u8 *)to, from, 1, ret, 1);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 2:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_size(*(u16 *)to, from, 2, ret, 2);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 4:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_size(*(u32 *)to, from, 4, ret, 4);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
|
@ -162,17 +162,17 @@ __copy_from_user(void *to, const void __user *from, unsigned long n)
|
|||
|
||||
switch (n) {
|
||||
case 1:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_size(*(u8 *)to, from, 1, ret, 1);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 2:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_size(*(u16 *)to, from, 2, ret, 2);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 4:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_size(*(u32 *)to, from, 4, ret, 4);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
|
@ -190,17 +190,17 @@ static __always_inline unsigned long __copy_from_user_nocache(void *to,
|
|||
|
||||
switch (n) {
|
||||
case 1:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_size(*(u8 *)to, from, 1, ret, 1);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 2:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_size(*(u16 *)to, from, 2, ret, 2);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 4:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_size(*(u32 *)to, from, 4, ret, 4);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
|
|
|
@ -57,31 +57,31 @@ int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size)
|
|||
return copy_user_generic(dst, (__force void *)src, size);
|
||||
switch (size) {
|
||||
case 1:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(*(u8 *)dst, (u8 __user *)src,
|
||||
ret, "b", "b", "=q", 1);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 2:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(*(u16 *)dst, (u16 __user *)src,
|
||||
ret, "w", "w", "=r", 2);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 4:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(*(u32 *)dst, (u32 __user *)src,
|
||||
ret, "l", "k", "=r", 4);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 8:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(*(u64 *)dst, (u64 __user *)src,
|
||||
ret, "q", "", "=r", 8);
|
||||
__uaccess_end();
|
||||
return ret;
|
||||
case 10:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(*(u64 *)dst, (u64 __user *)src,
|
||||
ret, "q", "", "=r", 10);
|
||||
if (likely(!ret))
|
||||
|
@ -91,7 +91,7 @@ int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size)
|
|||
__uaccess_end();
|
||||
return ret;
|
||||
case 16:
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(*(u64 *)dst, (u64 __user *)src,
|
||||
ret, "q", "", "=r", 16);
|
||||
if (likely(!ret))
|
||||
|
@ -190,7 +190,7 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
|
|||
switch (size) {
|
||||
case 1: {
|
||||
u8 tmp;
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(tmp, (u8 __user *)src,
|
||||
ret, "b", "b", "=q", 1);
|
||||
if (likely(!ret))
|
||||
|
@ -201,7 +201,7 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
|
|||
}
|
||||
case 2: {
|
||||
u16 tmp;
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(tmp, (u16 __user *)src,
|
||||
ret, "w", "w", "=r", 2);
|
||||
if (likely(!ret))
|
||||
|
@ -213,7 +213,7 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
|
|||
|
||||
case 4: {
|
||||
u32 tmp;
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(tmp, (u32 __user *)src,
|
||||
ret, "l", "k", "=r", 4);
|
||||
if (likely(!ret))
|
||||
|
@ -224,7 +224,7 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
|
|||
}
|
||||
case 8: {
|
||||
u64 tmp;
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
__get_user_asm(tmp, (u64 __user *)src,
|
||||
ret, "q", "", "=r", 8);
|
||||
if (likely(!ret))
|
||||
|
|
|
@ -570,7 +570,7 @@ do { \
|
|||
unsigned long __copy_to_user_ll(void __user *to, const void *from,
|
||||
unsigned long n)
|
||||
{
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
if (movsl_is_ok(to, from, n))
|
||||
__copy_user(to, from, n);
|
||||
else
|
||||
|
@ -583,7 +583,7 @@ EXPORT_SYMBOL(__copy_to_user_ll);
|
|||
unsigned long __copy_from_user_ll(void *to, const void __user *from,
|
||||
unsigned long n)
|
||||
{
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
if (movsl_is_ok(to, from, n))
|
||||
__copy_user_zeroing(to, from, n);
|
||||
else
|
||||
|
@ -596,7 +596,7 @@ EXPORT_SYMBOL(__copy_from_user_ll);
|
|||
unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
|
||||
unsigned long n)
|
||||
{
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
if (movsl_is_ok(to, from, n))
|
||||
__copy_user(to, from, n);
|
||||
else
|
||||
|
@ -610,7 +610,7 @@ EXPORT_SYMBOL(__copy_from_user_ll_nozero);
|
|||
unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from,
|
||||
unsigned long n)
|
||||
{
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
#ifdef CONFIG_X86_INTEL_USERCOPY
|
||||
if (n > 64 && cpu_has_xmm2)
|
||||
n = __copy_user_zeroing_intel_nocache(to, from, n);
|
||||
|
@ -627,7 +627,7 @@ EXPORT_SYMBOL(__copy_from_user_ll_nocache);
|
|||
unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
|
||||
unsigned long n)
|
||||
{
|
||||
__uaccess_begin();
|
||||
__uaccess_begin_nospec();
|
||||
#ifdef CONFIG_X86_INTEL_USERCOPY
|
||||
if (n > 64 && cpu_has_xmm2)
|
||||
n = __copy_user_intel_nocache(to, from, n);
|
||||
|
|
Loading…
Reference in New Issue
Block a user