From: Dave Chinner <dchinner@xxxxxxxxxx> Similar to FI_DEDUPERANGE, make copy_file_range() check that we have write permissions to the destination inode. Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> --- mm/filemap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index 0a170425935b..876df5275514 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3013,6 +3013,11 @@ int generic_copy_file_checks(struct file *file_in, loff_t pos_in, (file_out->f_flags & O_APPEND)) return -EBADF; + /* may sure we really are allowed to write to the destination inode */ + ret = inode_permission(inode_out, MAY_WRITE); + if (ret < 0) + return ret; + /* Ensure offsets don't wrap. */ if (pos_in + count < pos_in || pos_out + count < pos_out) return -EOVERFLOW; -- 2.19.1
