On Mon, Jul 1, 2024, at 12:19, Naresh Kamboju wrote:
fs/proc/task_mmu.c: In function 'do_procmap_query': fs/proc/task_mmu.c:598:48: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] 598 | if (karg.vma_name_size && copy_to_user((void __user *)karg.vma_name_addr, | ^ fs/proc/task_mmu.c:605:48: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] 605 | if (karg.build_id_size && copy_to_user((void __user *)karg.build_id_addr, | ^ cc1: all warnings being treated as errors
There is already a fix in linux-next:
@@ -595,14 +595,14 @@ static int do_procmap_query(struct proc_maps_private *priv, void __user *uarg) query_vma_teardown(mm, vma); mmput(mm);
- if (karg.vma_name_size && copy_to_user((void __user *)karg.vma_name_addr, + if (karg.vma_name_size && copy_to_user((void __user *)(uintptr_t)karg.vma_name_addr, name, karg.vma_name_size)) { kfree(name_buf); return -EFAULT; }
This could be expressed slightly nicer using u64_to_user_ptr(), but functionally that is the same.
I also see a slight issue in the use of .compat_ioctl:
const struct file_operations proc_pid_maps_operations = { .open = pid_maps_open, .read = seq_read, .llseek = seq_lseek, .release = proc_map_release, + .unlocked_ioctl = procfs_procmap_ioctl, + .compat_ioctl = procfs_procmap_ioctl, };
Since the argument is always a pointer, this should be
.compat_ioctl = compat_ptr_ioctl,
In practice this is only relevant on 32-bit s390 tasks to sanitize the pointer value.
Arnd