From 2d8ce70a08fe033c904115d59276ad86adeaa337 Mon Sep 17 00:00:00 2001 From: Goffredo Baroncelli Date: Tue, 3 Oct 2017 19:31:10 +0200 Subject: [PATCH] btrfs: avoid overflow when sector_t is 32 bit 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 Tested-by: Jean-Denis Girard Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 3738d245518cad..8dfa181b1a9271 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -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;