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>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index bb0dfb1..c25639e 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -390,9 +390,17 @@
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 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);