diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2015-11-19 13:29:28 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2015-11-19 13:47:10 -0800 |
| commit | 2e6edc95382cc36423aff18a237173ad62d5ab52 (patch) | |
| tree | 9f84c800ae12028682eeb720cfc2713bd704e4bc | |
| parent | 0df9d41ab5d43dc5b20abc8b22a6b6d098b03994 (diff) | |
block: protect rw_page against device teardown
Fix use after free crashes like the following:
general protection fault: 0000 [#1] SMP
Call Trace:
[<ffffffffa0050216>] ? pmem_do_bvec.isra.12+0xa6/0xf0 [nd_pmem]
[<ffffffffa0050ba2>] pmem_rw_page+0x42/0x80 [nd_pmem]
[<ffffffff8128fd90>] bdev_read_page+0x50/0x60
[<ffffffff812972f0>] do_mpage_readpage+0x510/0x770
[<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
[<ffffffff811d86dc>] ? lru_cache_add+0x1c/0x50
[<ffffffff81297657>] mpage_readpages+0x107/0x170
[<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
[<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
[<ffffffff8129058d>] blkdev_readpages+0x1d/0x20
[<ffffffff811d615f>] __do_page_cache_readahead+0x28f/0x310
[<ffffffff811d6039>] ? __do_page_cache_readahead+0x169/0x310
[<ffffffff811c5abd>] ? pagecache_get_page+0x2d/0x1d0
[<ffffffff811c76f6>] filemap_fault+0x396/0x530
[<ffffffff811f816e>] __do_fault+0x4e/0xf0
[<ffffffff811fce7d>] handle_mm_fault+0x11bd/0x1b50
Cc: <stable@vger.kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Matthew Wilcox <willy@linux.intel.com>
[willy: symmetry fixups]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| -rw-r--r-- | block/blk.h | 2 | ||||
| -rw-r--r-- | fs/block_dev.c | 18 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 2 |
3 files changed, 18 insertions, 4 deletions
diff --git a/block/blk.h b/block/blk.h index da722eb786df..c43926d3d74d 100644 --- a/block/blk.h +++ b/block/blk.h @@ -72,8 +72,6 @@ void blk_dequeue_request(struct request *rq); void __blk_queue_free_tags(struct request_queue *q); bool __blk_end_bidi_request(struct request *rq, int error, unsigned int nr_bytes, unsigned int bidi_bytes); -int blk_queue_enter(struct request_queue *q, gfp_t gfp); -void blk_queue_exit(struct request_queue *q); void blk_freeze_queue(struct request_queue *q); static inline void blk_queue_enter_live(struct request_queue *q) diff --git a/fs/block_dev.c b/fs/block_dev.c index bb0dfb1c7af1..c25639e907bd 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -390,9 +390,17 @@ int bdev_read_page(struct block_device *bdev, sector_t sector, struct page *page) { const struct block_device_operations *ops = bdev->bd_disk->fops; + int result = -EOPNOTSUPP; + if (!ops->rw_page || bdev_get_integrity(bdev)) - return -EOPNOTSUPP; - return ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ); + return result; + + result = blk_queue_enter(bdev->bd_queue, GFP_KERNEL); + if (result) + return result; + result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ); + blk_queue_exit(bdev->bd_queue); + return result; } EXPORT_SYMBOL_GPL(bdev_read_page); @@ -421,14 +429,20 @@ int bdev_write_page(struct block_device *bdev, sector_t sector, int result; int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE; const struct block_device_operations *ops = bdev->bd_disk->fops; + if (!ops->rw_page || bdev_get_integrity(bdev)) return -EOPNOTSUPP; + result = blk_queue_enter(bdev->bd_queue, GFP_KERNEL); + if (result) + return result; + set_page_writeback(page); result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw); if (result) end_page_writeback(page); else unlock_page(page); + blk_queue_exit(bdev->bd_queue); return result; } EXPORT_SYMBOL_GPL(bdev_write_page); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3fe27f8d91f0..c0d2b7927c1f 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -794,6 +794,8 @@ extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, struct scsi_ioctl_command __user *); +extern int blk_queue_enter(struct request_queue *q, gfp_t gfp); +extern void blk_queue_exit(struct request_queue *q); extern void blk_start_queue(struct request_queue *q); extern void blk_stop_queue(struct request_queue *q); extern void blk_sync_queue(struct request_queue *q); |