From 10097449f40604d121f5854b063b62dfcaaa669a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 9 Jun 2021 16:40:24 +0800 Subject: [PATCH] block: take bd_mutex around delete_partitions in del_gendisk mainline inclusion from mainline-v5.13-rc1 commit c76f48eb5c084b1e15c931ae8cc1826cd771d70d category: bugfix bugzilla: 55097 CVE: NA -------------------------------- There is nothing preventing an ioctl from trying do delete partition concurrenly with del_gendisk, so take open_mutex to serialize against that. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210406062303.811835-6-hch@lst.de Signed-off-by: Jens Axboe Conflicts: block/genhd.c block/partitions/core.c [Yufen: linux-4.19 have not extract blk_drop_partitions().] Signed-off-by: Yufen Yu Reviewed-by: Jason Yan Signed-off-by: Yang Yingliang --- block/genhd.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/block/genhd.c b/block/genhd.c index 8df6420194a0..2127d2900341 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -747,6 +747,7 @@ void del_gendisk(struct gendisk *disk) { struct disk_part_iter piter; struct hd_struct *part; + struct block_device *bdev; blk_integrity_del(disk); disk_del_events(disk); @@ -756,6 +757,14 @@ void del_gendisk(struct gendisk *disk) * disk is marked as dead (GENHD_FL_UP cleared). */ down_write(&disk->lookup_sem); + + /* + * If bdev is null, that menas memory allocate fail. Then + * add_partitions can also fail. + */ + bdev = bdget_disk(disk, 0); + if (bdev) + mutex_lock(&bdev->bd_mutex); /* invalidate stuff */ disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE); @@ -765,6 +774,8 @@ void del_gendisk(struct gendisk *disk) delete_partition(disk, part->partno); } disk_part_iter_exit(&piter); + if (bdev) + mutex_unlock(&bdev->bd_mutex); invalidate_partition(disk, 0); bdev_unhash_inode(disk_devt(disk)); -- GitLab