Commit-ID: a6cbfbe6677efb5ca47bb7958c2718236c25126e
Gitweb: https://git.kernel.org/tip/a6cbfbe6677efb5ca47bb7958c2718236c25126e
Author: Jann Horn <jannh@xxxxxxxxxx>
AuthorDate: Fri, 29 Mar 2019 22:46:52 +0100
Committer: Borislav Petkov <bp@xxxxxxx>
CommitDate: Wed, 3 Apr 2019 16:26:17 +0200
x86/uaccess: Fix implicit cast of __user pointer
The first two arguments of __user_atomic_cmpxchg_inatomic() are:
- @uval is a kernel pointer into which the old value should be stored
- @ptr is the user pointer on which the cmpxchg should operate
This means that casting @uval to __typeof__(ptr) is wrong. Since @uval
is only used once inside the macro, just get rid of __uval and use
(uval) directly.
Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Mukesh Ojha <mojha@xxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Qiaowei Ren <qiaowei.ren@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: x86-ml <x86@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190329214652.258477-4-jannh@xxxxxxxxxx
---
arch/x86/include/asm/uaccess.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 1954dd5552a2..a21f2a2f17bf 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -585,7 +585,6 @@ extern void __cmpxchg_wrong_size(void)
#define __user_atomic_cmpxchg_inatomic(uval, ptr, old, new, size) \
({ \
int __ret = 0; \
- __typeof__(ptr) __uval = (uval); \
__typeof__(*(ptr)) __old = (old); \
__typeof__(*(ptr)) __new = (new); \
__uaccess_begin_nospec(); \
@@ -661,7 +660,7 @@ extern void __cmpxchg_wrong_size(void)
__cmpxchg_wrong_size(); \
} \
__uaccess_end(); \
- *__uval = __old; \
+ *(uval) = __old; \
__ret; \
})
|