diff options
author | Luis Chamberlain <mcgrof@kernel.org> | 2021-09-27 15:02:52 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-17 11:03:51 +0100 |
commit | ca9ae3fb33154b8c6e679dbb7be047c545d0d8e3 (patch) | |
tree | c9b6456b869e149a67ac5b23b6d7f4d14d7448d0 /drivers/block | |
parent | 8a6e8aa372073ea644ac7ffc9e5a428d6717c57e (diff) |
floppy: fix calling platform_device_unregister() on invalid drives
[ Upstream commit 662167e59d2f3c15a44a88088fc6c1a67c8a3650 ]
platform_device_unregister() should only be called when
a respective platform_device_register() is called. However
the floppy driver currently allows failures when registring
a drive and a bail out could easily cause an invalid call
to platform_device_unregister() where it was not intended.
Fix this by adding a bool to keep track of when the platform
device was registered for a drive.
This does not fix any known panic / bug. This issue was found
through code inspection while preparing the driver to use the
up and coming support for device_add_disk() error handling.
From what I can tell from code inspection, chances of this
ever happening should be insanely small, perhaps OOM.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220302.1073499-5-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/floppy.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index fef79ea52e3e..fb2aafabfebc 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4478,6 +4478,7 @@ static const struct blk_mq_ops floppy_mq_ops = { }; static struct platform_device floppy_device[N_DRIVE]; +static bool registered[N_DRIVE]; static bool floppy_available(int drive) { @@ -4693,6 +4694,8 @@ static int __init do_floppy_init(void) if (err) goto out_remove_drives; + registered[drive] = true; + device_add_disk(&floppy_device[drive].dev, disks[drive][0], NULL); } @@ -4703,7 +4706,8 @@ out_remove_drives: while (drive--) { if (floppy_available(drive)) { del_gendisk(disks[drive][0]); - platform_device_unregister(&floppy_device[drive]); + if (registered[drive]) + platform_device_unregister(&floppy_device[drive]); } } out_release_dma: @@ -4946,7 +4950,8 @@ static void __exit floppy_module_exit(void) if (disks[drive][i]) del_gendisk(disks[drive][i]); } - platform_device_unregister(&floppy_device[drive]); + if (registered[drive]) + platform_device_unregister(&floppy_device[drive]); } for (i = 0; i < ARRAY_SIZE(floppy_type); i++) { if (disks[drive][i]) |