mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/
synced 2026-09-26 18:16:26 +00:00
No description
- C 96.9%
- Assembly 0.9%
- Rust 0.6%
- Shell 0.6%
- Python 0.5%
- Other 0.3%
897366537f
When two blkdev_open() calls race with device removal and recreation,
__blkdev_get() can use looked up gendisk after it is freed:
CPU0 CPU1 CPU2
del_gendisk(disk);
bdev_unhash_inode(inode);
blkdev_open() blkdev_open()
bdev = bd_acquire(inode);
- creates and returns new inode
bdev = bd_acquire(inode);
- returns the same inode
__blkdev_get(devt) __blkdev_get(devt)
disk = get_gendisk(devt);
- got structure of device going away
<finish device removal>
<new device gets
created under the same
device number>
disk = get_gendisk(devt);
- got new device structure
if (!bdev->bd_openers) {
does the first open
}
if (!bdev->bd_openers)
- false
} else {
put_disk_and_module(disk)
- remember this was old device - this was last ref and disk is
now freed
}
disk_unblock_events(disk); -> oops
Fix the problem by making sure we drop reference to disk in
__blkdev_get() only after we are really done with it.
Reported-by: Hou Tao <houtao1@huawei.com>
Tested-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
History
|
|
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.