From: Zhong Jinghua <zhongjinghua@xxxxxxxxxx>
In the block_ioctl, we can pass in the unsigned number 0x8000000000000000
as an input parameter, like below:
block_ioctl
blkdev_ioctl
blkpg_ioctl
blkpg_do_ioctl
copy_from_user
bdev_add_partition
add_partition
p->start_sect = start; // start = 0x8000000000000000
Then, there was an warning when submit bio:
WARNING: CPU: 0 PID: 382 at fs/iomap/apply.c:54
Call trace:
iomap_apply+0x644/0x6e0
__iomap_dio_rw+0x5cc/0xa24
iomap_dio_rw+0x4c/0xcc
ext4_dio_read_iter
ext4_file_read_iter
ext4_file_read_iter+0x318/0x39c
call_read_iter
lo_rw_aio.isra.0+0x748/0x75c
do_req_filebacked+0x2d4/0x370
loop_handle_cmd
loop_queue_work+0x94/0x23c
kthread_worker_fn+0x160/0x6bc
loop_kthread_worker_fn+0x3c/0x50
kthread+0x20c/0x25c
ret_from_fork+0x10/0x18
Stack:
submit_bio_noacct
submit_bio_checks
blk_partition_remap
bio->bi_iter.bi_sector += p->start_sect
// bio->bi_iter.bi_sector = 0xffc0000000000000 + 65408
..
loop_queue_work
loop_handle_cmd
do_req_filebacked
pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset // pos < 0
lo_rw_aio
call_read_iter
ext4_dio_read_iter
__iomap_dio_rw
iomap_apply
ext4_iomap_begin
map.m_lblk = offset >> blkbits
ext4_set_iomap
iomap->offset = (u64) map->m_lblk << blkbits
// iomap->offset = 64512
WARN_ON(iomap.offset > pos) // iomap.offset = 64512 and pos < 0
This is unreasonable for start + length > disk->part0.nr_sects. There is
already a similar check in blk_add_partition().
Fix it by adding a check in bdev_add_partition().
Reported-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
Signed-off-by: Zhong Jinghua <zhongjinghua@xxxxxxxxxx>
---
block/ioctl.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/block/ioctl.c b/block/ioctl.c
index 9c5f637ff153..3223ea862523 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -33,9 +33,16 @@ static int blkpg_do_ioctl(struct block_device *bdev,
if (op == BLKPG_DEL_PARTITION)
return bdev_del_partition(disk, p.pno);
+ if (p.start < 0 || p.length <= 0 || p.start + p.length < 0)
+ return -EINVAL;
+
start = p.start >> SECTOR_SHIFT;
length = p.length >> SECTOR_SHIFT;
+ /* length may be equal to 0 after right shift */
+ if (!length || start + length > get_capacity(bdev->bd_disk))
+ return -EINVAL;
+
switch (op) {
case BLKPG_ADD_PARTITION:
/* check if partition is aligned to blocksize */
--
2.31.1
