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authorAl Viro <viro@zeniv.linux.org.uk>2019-10-09 22:21:05 +0300
committerMax Filippov <jcmvbkbc@gmail.com>2019-10-14 21:39:50 +0300
commit6595d144decec396bf2e2efee27e50634a4b627f (patch)
tree91dfc29dc79a7a8d7e33df00b784e36ac5597b0b /arch/xtensa
parent4f5cafb5cb8471e54afdc9054d973535614f7675 (diff)
downloadlinux-6595d144decec396bf2e2efee27e50634a4b627f.tar.xz
xtensa: fix {get,put}_user() for 64bit values
First of all, on short copies __copy_{to,from}_user() return the amount of bytes left uncopied, *not* -EFAULT. get_user() and put_user() are expected to return -EFAULT on failure. Another problem is get_user(v32, (__u64 __user *)p); that should fetch 64bit value and the assign it to v32, truncating it in process. Current code, OTOH, reads 8 bytes of data and stores them at the address of v32, stomping on the 4 bytes that follow v32 itself. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa')
-rw-r--r--arch/xtensa/include/asm/uaccess.h13
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h
index 6792928ba84a..f568c00392ec 100644
--- a/arch/xtensa/include/asm/uaccess.h
+++ b/arch/xtensa/include/asm/uaccess.h
@@ -100,7 +100,7 @@ do { \
case 4: __put_user_asm(x, ptr, retval, 4, "s32i", __cb); break; \
case 8: { \
__typeof__(*ptr) __v64 = x; \
- retval = __copy_to_user(ptr, &__v64, 8); \
+ retval = __copy_to_user(ptr, &__v64, 8) ? -EFAULT : 0; \
break; \
} \
default: __put_user_bad(); \
@@ -198,7 +198,16 @@ do { \
case 1: __get_user_asm(x, ptr, retval, 1, "l8ui", __cb); break;\
case 2: __get_user_asm(x, ptr, retval, 2, "l16ui", __cb); break;\
case 4: __get_user_asm(x, ptr, retval, 4, "l32i", __cb); break;\
- case 8: retval = __copy_from_user(&x, ptr, 8); break; \
+ case 8: { \
+ u64 __x; \
+ if (unlikely(__copy_from_user(&__x, ptr, 8))) { \
+ retval = -EFAULT; \
+ (x) = 0; \
+ } else { \
+ (x) = *(__force __typeof__((ptr)))&__x; \
+ } \
+ break; \
+ } \
default: (x) = __get_user_bad(); \
} \
} while (0)