Patch "btrfs: avoid overflow when sector_t is 32 bit" has been added to the 4.13-stable tree

This is a note to let you know that I've just added the patch titled

btrfs: avoid overflow when sector_t is 32 bit

to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
btrfs-avoid-overflow-when-sector_t-is-32-bit.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Goffredo Baroncelli <[email protected]>
Date: Tue, 3 Oct 2017 19:31:10 +0200
Subject: btrfs: avoid overflow when sector_t is 32 bit

From: Goffredo Baroncelli <[email protected]>

commit 2d8ce70a08fe033c904115d59276ad86adeaa337 upstream.

Jean-Denis Girard noticed commit c821e7f3 "pass bytes to btrfs_bio_alloc" (https://patchwork.kernel.org/patch/9763081/)
introduces a regression on 32 bit machines.
When CONFIG_LBDAF is _not_ defined (CONFIG_LBDAF == Support for large (2TB+) block devices and files) sector_t is 32 bit on 32bit machines.

In the function submit_extent_page, 'sector' (which is sector_t type) is multiplied by 512 to convert it from sectors to bytes, leading to an overflow when the disk is bigger than 4GB (!).

I added a cast to u64 to avoid overflow.

---
 fs/btrfs/extent_io.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -2799,7 +2799,7 @@ static int submit_extent_page(int op, in
 		}
 	}
 
-	bio = btrfs_bio_alloc(bdev, sector << 9);
+	bio = btrfs_bio_alloc(bdev, (u64)sector << 9);
 	bio_add_page(bio, page, page_size, offset);
 	bio->bi_end_io = end_io_func;
 	bio->bi_private = tree;

Patches currently in stable-queue which might be from [email protected] are

queue-4.13/btrfs-avoid-overflow-when-sector_t-is-32-bit.patch