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x86, smap: Handle csum_partial_copy_*_user() 

Add SMAP annotations to csum_partial_copy_to/from_user().  These
functions legitimately access user space and thus need to set the AC
flag.

TODO: add explicit checks that the side with the kernel space pointer
really points into kernel space.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-2aps0u00eer658fd5xyanan7@git.kernel.org
Cc: <stable@vger.kernel.org> # v3.7+
This commit is contained in:
H. Peter Anvin 2013-08-30 15:43:03 -07:00
parent d8dfad3876
commit 7263dda41b
2 changed files with 27 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
arch/x86/include/asm/checksum_32.h
View File

@ -49,9 +49,15 @@ static inline __wsum csum_partial_copy_from_user(const void __user *src,
int len, __wsum sum,
int *err_ptr)
{
__wsum ret;
might_sleep();
return csum_partial_copy_generic((__force void *)src, dst,
len, sum, err_ptr, NULL);
stac();
ret = csum_partial_copy_generic((__force void *)src, dst,
len, sum, err_ptr, NULL);
clac();
return ret;
}
/*
@ -176,10 +182,16 @@ static inline __wsum csum_and_copy_to_user(const void *src,
int len, __wsum sum,
int *err_ptr)
{
__wsum ret;
might_sleep();
if (access_ok(VERIFY_WRITE, dst, len))
return csum_partial_copy_generic(src, (__force void *)dst,
len, sum, NULL, err_ptr);
if (access_ok(VERIFY_WRITE, dst, len)) {
stac();
ret = csum_partial_copy_generic(src, (__force void *)dst,
len, sum, NULL, err_ptr);
clac();
return ret;
}
if (len)
*err_ptr = -EFAULT;

12
arch/x86/lib/csum-wrappers_64.c
View File

@ -6,6 +6,7 @@
*/
#include <asm/checksum.h>
#include <linux/module.h>
#include <asm/smap.h>
/**
* csum_partial_copy_from_user - Copy and checksum from user space.
@ -52,8 +53,10 @@ csum_partial_copy_from_user(const void __user *src, void *dst,
len -= 2;
}
}
stac();
isum = csum_partial_copy_generic((__force const void *)src,
dst, len, isum, errp, NULL);
clac();
if (unlikely(*errp))
goto out_err;
@ -82,6 +85,8 @@ __wsum
csum_partial_copy_to_user(const void *src, void __user *dst,
int len, __wsum isum, int *errp)
{
__wsum ret;
might_sleep();
if (unlikely(!access_ok(VERIFY_WRITE, dst, len))) {
@ -105,8 +110,11 @@ csum_partial_copy_to_user(const void *src, void __user *dst,
}
*errp = 0;
return csum_partial_copy_generic(src, (void __force *)dst,
len, isum, NULL, errp);
stac();
ret = csum_partial_copy_generic(src, (void __force *)dst,
len, isum, NULL, errp);
clac();
return ret;
}
EXPORT_SYMBOL(csum_partial_copy_to_user);