do_pages_move does not handle compat pointers for the page list.
correctly. Add in_compat_syscall check and appropriate get_user
fetch when iterating the page list.
Fixes: 5b1b561ba73c ("mm: simplify compat_sys_move_pages")
Signed-off-by: Gregory Price <gregory.price@xxxxxxxxxxxx>
Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Co-developed-by: Arnd Bergmann <arnd@xxxxxxxx>
---
mm/migrate.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index 2053b54556ca..06086dc9da28 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2162,6 +2162,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
const int __user *nodes,
int __user *status, int flags)
{
+ compat_uptr_t __user *compat_pages = (void __user *)pages;
int current_node = NUMA_NO_NODE;
LIST_HEAD(pagelist);
int start, i;
@@ -2174,8 +2175,17 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
int node;
err = -EFAULT;
- if (get_user(p, pages + i))
- goto out_flush;
+ if (in_compat_syscall()) {
+ compat_uptr_t cp;
+
+ if (get_user(cp, compat_pages + i))
+ goto out_flush;
+
+ p = compat_ptr(cp);
+ } else {
+ if (get_user(p, pages + i))
+ goto out_flush;
+ }
if (get_user(node, nodes + i))
goto out_flush;
--
2.39.1
