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authorJun'ichi Nomura <j-nomura@ce.jp.nec.com>2012-03-02 10:38:33 +0100
committerJens Axboe <axboe@kernel.dk>2012-03-02 10:38:33 +0100
commitfe316bf2d5847bc5dd975668671a7b1067603bc7 (patch)
tree617f6a89b96a8c074d0a2fc1ef4ffc259fb4ed2f /fs/block_dev.c
parent621032ad6eaabf2fe771c4fa0d8f58e1fcfcdba6 (diff)
downloadlinux-fe316bf2d5847bc5dd975668671a7b1067603bc7.tar.bz2
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.c16
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;
}