Call remap_verify_area() on the source file as well as the destination.
When called from vfs_dedupe_file_range() the check as already been
performed, but not so if called from layered fs (overlayfs, etc...)
Could ommit the redundant check in vfs_dedupe_file_range(), but leave for
now to get error early (for fear of breaking backward compatibility).
This call shouldn't be performance sensitive.
Signed-off-by: Miklos Szeredi <[email protected]>
---
fs/remap_range.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/remap_range.c b/fs/remap_range.c
index e6099beefa97..77dba3a49e65 100644
--- a/fs/remap_range.c
+++ b/fs/remap_range.c
@@ -456,8 +456,16 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
if (ret)
return ret;
+ /*
+ * This is redundant if called from vfs_dedupe_file_range(), but other
+ * callers need it and it's not performance sesitive...
+ */
+ ret = remap_verify_area(src_file, src_pos, len, false);
+ if (ret)
+ goto out_drop_write;
+
ret = remap_verify_area(dst_file, dst_pos, len, true);
- if (ret < 0)
+ if (ret)
goto out_drop_write;
ret = -EPERM;
--
2.26.2