diff --git a/drivers/android/binder/thread.rs b/drivers/android/binder/thread.rs index 7e34ccd394f8..33a9053b6adf 100644 --- a/drivers/android/binder/thread.rs +++ b/drivers/android/binder/thread.rs @@ -69,17 +69,24 @@ struct ScatterGatherEntry { } /// This entry specifies that a fixup should happen at `target_offset` of the -/// buffer. If `skip` is nonzero, then the fixup is a `binder_fd_array_object` -/// and is applied later. Otherwise if `skip` is zero, then the size of the -/// fixup is `sizeof::()` and `pointer_value` is written to the buffer. -struct PointerFixupEntry { - /// The number of bytes to skip, or zero for a `binder_buffer_object` fixup. - skip: usize, - /// The translated pointer to write when `skip` is zero. - pointer_value: u64, - /// The offset at which the value should be written. The offset is relative - /// to the original buffer. - target_offset: usize, +/// buffer. +enum PointerFixupEntry { + /// A fixup for a `binder_buffer_object`. + Fixup { + /// The translated pointer to write. + pointer_value: u64, + /// The offset at which the value should be written. The offset is relative + /// to the original buffer. + target_offset: usize, + }, + /// A skip for a `binder_fd_array_object`. + Skip { + /// The number of bytes to skip. + skip: usize, + /// The offset at which the skip should happen. The offset is relative + /// to the original buffer. + target_offset: usize, + }, } /// Return type of `apply_and_validate_fixup_in_parent`. @@ -762,8 +769,7 @@ impl Thread { parent_entry.fixup_min_offset = info.new_min_offset; parent_entry.pointer_fixups.push( - PointerFixupEntry { - skip: 0, + PointerFixupEntry::Fixup { pointer_value: buffer_ptr_in_user_space, target_offset: info.target_offset, }, @@ -807,9 +813,8 @@ impl Thread { parent_entry .pointer_fixups .push( - PointerFixupEntry { + PointerFixupEntry::Skip { skip: fds_len, - pointer_value: 0, target_offset: info.target_offset, }, GFP_KERNEL, @@ -871,17 +876,21 @@ impl Thread { let mut reader = UserSlice::new(UserPtr::from_addr(sg_entry.sender_uaddr), sg_entry.length).reader(); for fixup in &mut sg_entry.pointer_fixups { - let fixup_len = if fixup.skip == 0 { - size_of::() - } else { - fixup.skip + let (fixup_len, fixup_offset) = match fixup { + PointerFixupEntry::Fixup { target_offset, .. } => { + (size_of::(), *target_offset) + } + PointerFixupEntry::Skip { + skip, + target_offset, + } => (*skip, *target_offset), }; - let target_offset_end = fixup.target_offset.checked_add(fixup_len).ok_or(EINVAL)?; - if fixup.target_offset < end_of_previous_fixup || offset_end < target_offset_end { + let target_offset_end = fixup_offset.checked_add(fixup_len).ok_or(EINVAL)?; + if fixup_offset < end_of_previous_fixup || offset_end < target_offset_end { pr_warn!( "Fixups oob {} {} {} {}", - fixup.target_offset, + fixup_offset, end_of_previous_fixup, offset_end, target_offset_end @@ -890,13 +899,13 @@ impl Thread { } let copy_off = end_of_previous_fixup; - let copy_len = fixup.target_offset - end_of_previous_fixup; + let copy_len = fixup_offset - end_of_previous_fixup; if let Err(err) = alloc.copy_into(&mut reader, copy_off, copy_len) { pr_warn!("Failed copying into alloc: {:?}", err); return Err(err.into()); } - if fixup.skip == 0 { - let res = alloc.write::(fixup.target_offset, &fixup.pointer_value); + if let PointerFixupEntry::Fixup { pointer_value, .. } = fixup { + let res = alloc.write::(fixup_offset, pointer_value); if let Err(err) = res { pr_warn!("Failed copying ptr into alloc: {:?}", err); return Err(err.into());