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| author | Jun'ichi Nomura <j-nomura@ce.jp.nec.com> | 2012-03-02 10:38:33 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2012-03-02 10:38:33 +0100 |
| commit | fe316bf2d5847bc5dd975668671a7b1067603bc7 (patch) | |
| tree | 617f6a89b96a8c074d0a2fc1ef4ffc259fb4ed2f /fs/block_dev.c | |
| parent | block: exit_io_context() should call elevator_exit_icq_fn() (diff) | |
| download | linux-fe316bf2d5847bc5dd975668671a7b1067603bc7.tar.xz linux-fe316bf2d5847bc5dd975668671a7b1067603bc7.zip | |
block: Fix NULL pointer dereference in sd_revalidate_disk
Since 2.6.39 (1196f8b), when a driver returns -ENOMEDIUM for open(),
__blkdev_get() calls rescan_partitions() to remove
in-kernel partition structures and raise KOBJ_CHANGE uevent.
However it ends up calling driver's revalidate_disk without open
and could cause oops.
In the case of SCSI:
process A process B
----------------------------------------------
sys_open
__blkdev_get
sd_open
returns -ENOMEDIUM
scsi_remove_device
<scsi_device torn down>
rescan_partitions
sd_revalidate_disk
<oops>
Oopses are reported here:
http://marc.info/?l=linux-scsi&m=132388619710052
This patch separates the partition invalidation from rescan_partitions()
and use it for -ENOMEDIUM case.
Reported-by: Huajun Li <huajun.li.lee@gmail.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 0e575d1304b4..5e9f198f7712 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1183,8 +1183,12 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) * The latter is necessary to prevent ghost * partitions on a removed medium. */ - if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM)) - rescan_partitions(disk, bdev); + if (bdev->bd_invalidated) { + if (!ret) + rescan_partitions(disk, bdev); + else if (ret == -ENOMEDIUM) + invalidate_partitions(disk, bdev); + } if (ret) goto out_clear; } else { @@ -1214,8 +1218,12 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) if (bdev->bd_disk->fops->open) ret = bdev->bd_disk->fops->open(bdev, mode); /* the same as first opener case, read comment there */ - if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM)) - rescan_partitions(bdev->bd_disk, bdev); + if (bdev->bd_invalidated) { + if (!ret) + rescan_partitions(bdev->bd_disk, bdev); + else if (ret == -ENOMEDIUM) + invalidate_partitions(bdev->bd_disk, bdev); + } if (ret) goto out_unlock_bdev; } |