diff options
| author | Andrey Ryabinin <a.ryabinin@samsung.com> | 2019-11-08 13:35:05 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-10 11:21:15 +0100 |
| commit | b4fe083f59a6f9911e00affd42fc42d046f11504 (patch) | |
| tree | 70221bd7bc485e078bb8f65af6cf9afc4b092d04 /arch/arm/include | |
| parent | e4cea4d4c5d9f5162c62bd1af102a781987489b6 (diff) | |
ARM: 8051/1: put_user: fix possible data corruption in put_user
Commit 537094b64b229bf3ad146042f83e74cf6abe59df upstream.
According to arm procedure call standart r2 register is call-cloberred.
So after the result of x expression was put into r2 any following
function call in p may overwrite r2. To fix this, the result of p
expression must be saved to the temporary variable before the
assigment x expression to __r2.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/include')
| -rw-r--r-- | arch/arm/include/asm/uaccess.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index cd8b589111ba..35c9db857ebe 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -251,7 +251,7 @@ extern int __put_user_8(void *, unsigned long long); ({ \ unsigned long __limit = current_thread_info()->addr_limit - 1; \ const typeof(*(p)) __user *__tmp_p = (p); \ - register typeof(*(p)) __r2 asm("r2") = (x); \ + register const typeof(*(p)) __r2 asm("r2") = (x); \ register const typeof(*(p)) __user *__p asm("r0") = __tmp_p; \ register unsigned long __l asm("r1") = __limit; \ register int __e asm("r0"); \ |