[PATCH 5.17 095/114] mm: mremap: fix sign for EFAULT error return value

Greg Kroah-Hartman
2022-05-16T20:33:13Z

From: Niels Dossche <dossche.niels@gmail.com>

commit 7d1e6496616275f3830e2f2f91fa69a66953e95b upstream.

The mremap syscall is supposed to return a pointer to the new virtual
memory area on success, and a negative value of the error code in case of
failure. Currently, EFAULT is returned when the VMA is not found, instead
of -EFAULT. The users of this syscall will therefore believe the syscall
succeeded in case the VMA didn't exist, as it returns a pointer to address
0xe (0xe being the value of EFAULT). Fix the sign of the error value.

Link: https://lkml.kernel.org/r/20220427224439.23828-2-dossche.niels@gmail.com
Fixes: 550a7d60bd5e ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
mm/mremap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -947,7 +947,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, a
return -EINTR;
vma = find_vma(mm, addr);
if (!vma || vma->vm_start > addr) {
- ret = EFAULT;
+ ret = -EFAULT;
goto out;
}