| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.13 137/160] btrfs: avoid overflow when sector_t is 32 bit | Date | Tue, 10 Oct 2017 21:51:05 +0200 |
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4.13-stable review patch. If anyone has any objections, please let me know.
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From: Goffredo Baroncelli <kreijack@inwind.it>
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.
Fixes: c821e7f3 ("btrfs: pass bytes to btrfs_bio_alloc") 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/btrfs/extent_io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -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;
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