diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2013-09-26 18:50:40 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-18 07:45:45 -0700 |
| commit | a683a93b1ce0b86944a51a1b8f787aa684836edb (patch) | |
| tree | ab37081886b889ab612bd8da08b868b2896b3a44 | |
| parent | 5cd12e7776183668bd92a5f5fe102113d3bb599a (diff) | |
ARC: Fix 32-bit wrap around in access_ok()
commit 0752adfda15f0eca9859a76da3db1800e129ad43 upstream.
Anton reported
| LTP tests syscalls/process_vm_readv01 and process_vm_writev01 fail
| similarly in one testcase test_iov_invalid -> lvec->iov_base.
| Testcase expects errno EFAULT and return code -1,
| but it gets return code 1 and ERRNO is 0 what means success.
Essentially test case was passing a pointer of -1 which access_ok()
was not catching. It was doing [@addr + @sz <= TASK_SIZE] which would
pass for @addr == -1
Fixed that by rewriting as [@addr <= TASK_SIZE - @sz]
Reported-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arc/include/asm/uaccess.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h index 32420824375..30c9baffa96 100644 --- a/arch/arc/include/asm/uaccess.h +++ b/arch/arc/include/asm/uaccess.h @@ -43,7 +43,7 @@ * Because it essentially checks if buffer end is within limit and @len is * non-ngeative, which implies that buffer start will be within limit too. * - * The reason for rewriting being, for majorit yof cases, @len is generally + * The reason for rewriting being, for majority of cases, @len is generally * compile time constant, causing first sub-expression to be compile time * subsumed. * @@ -53,7 +53,7 @@ * */ #define __user_ok(addr, sz) (((sz) <= TASK_SIZE) && \ - (((addr)+(sz)) <= get_fs())) + ((addr) <= (get_fs() - (sz)))) #define __access_ok(addr, sz) (unlikely(__kernel_ok) || \ likely(__user_ok((addr), (sz)))) |