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btrfs: avoid overflow when sector_t is 32 bit

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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.

Fixes: c821e7f3 ("btrfs: pass bytes to btrfs_bio_alloc")
CC: stable@vger.kernel.org # 4.13+
Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Goffredo Baroncelli 2017-10-03 19:31:10 +02:00 committed by David Sterba
parent 8c6c592831
commit 2d8ce70a08
1 changed files with 1 additions and 1 deletions
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2
fs/btrfs/extent_io.c
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@ -2801,7 +2801,7 @@ static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
}
}
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;