[PATCH] block: fix error unwinding in device_add_disk
flat view
STALE1760d
LANDED: 1 (0M)
From: Christoph Hellwig <hch@lst.de>
Date: 2021-12-21 16:18:58
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
1 review trailer; landed in mainline as 99d8690aae4b on 2021-12-21.
One device_add is called disk->ev will be freed by disk_release, so we
should free it twice. Fix this by allocating disk->ev after device_add
so that the extra local unwinding can be removed entirely.
Based on an earlier patch from Tetsuo Handa.
Reported-by: syzbot <redacted>
Tested-by: syzbot <redacted>
Fixes: 83cbce9574462c6b ("block: add error handling for device_add_disk / add_disk")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/genhd.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/block/genhd.c b/block/genhd.c
index 3c139a1b6f049..603db5d6f10c0 100644
--- a/block/genhd.c
+++ b/block/genhd.c@@ -442,10 +442,6 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk, disk->first_minor = ret; } - ret = disk_alloc_events(disk); - if (ret) - goto out_free_ext_minor; - /* delay uevents, until we scanned partition table */ dev_set_uevent_suppress(ddev, 1);
@@ -456,7 +452,12 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk, ddev->devt = MKDEV(disk->major, disk->first_minor); ret = device_add(ddev); if (ret) - goto out_disk_release_events; + goto out_free_ext_minor; + + ret = disk_alloc_events(disk); + if (ret) + goto out_device_del; + if (!sysfs_deprecated) { ret = sysfs_create_link(block_depr, &ddev->kobj, kobject_name(&ddev->kobj));
@@ -538,8 +539,6 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk, sysfs_remove_link(block_depr, dev_name(ddev)); out_device_del: device_del(ddev); -out_disk_release_events: - disk_release_events(disk); out_free_ext_minor: if (disk->major == BLOCK_EXT_MAJOR) blk_free_ext_minor(disk->first_minor);
--
2.30.2