From 10172f200b67aafcb9b8ce7d0575d713c1aafbb7 Mon Sep 17 00:00:00 2001 From: Jon Derrick Date: Fri, 24 Feb 2023 11:33:22 -0700 Subject: [PATCH] md: Fix types in sb writer Page->index is a pgoff_t and multiplying could cause overflows on a 32-bit architecture. In the sb writer, this is used to calculate and verify the sector being used, and is multiplied by a sector value. Using sector_t will cast it to a u64 type and is the more appropriate type for the unit. Additionally, the integer size unit is converted to a sector unit in later calculations, and is now corrected to be an unsigned type. Finally, clean up the calculations using variable aliases to improve readabiliy. Reviewed-by: Christoph Hellwig Signed-off-by: Jon Derrick Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230224183323.638-3-jonathan.derrick@linux.dev --- drivers/md/md-bitmap.c | 35 ++++++++++++++--------------------- 1 file changed, 14 insertions(+), 21 deletions(-) diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index cdc61e6..bf250a5 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -215,12 +215,13 @@ static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap, struct block_device *bdev; struct mddev *mddev = bitmap->mddev; struct bitmap_storage *store = &bitmap->storage; - loff_t offset = mddev->bitmap_info.offset; - int size = PAGE_SIZE; + sector_t offset = mddev->bitmap_info.offset; + sector_t ps, sboff, doff; + unsigned int size = PAGE_SIZE; bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev; if (page->index == store->file_pages - 1) { - int last_page_size = store->bytes & (PAGE_SIZE - 1); + unsigned int last_page_size = store->bytes & (PAGE_SIZE - 1); if (last_page_size == 0) last_page_size = PAGE_SIZE; @@ -228,43 +229,35 @@ static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap, bdev_logical_block_size(bdev)); } + ps = page->index * PAGE_SIZE / SECTOR_SIZE; + sboff = rdev->sb_start + offset; + doff = rdev->data_offset; + /* Just make sure we aren't corrupting data or metadata */ if (mddev->external) { /* Bitmap could be anywhere. */ - if (rdev->sb_start + offset - + (page->index * (PAGE_SIZE / SECTOR_SIZE)) - > rdev->data_offset && - rdev->sb_start + offset - < (rdev->data_offset + mddev->dev_sectors - + (PAGE_SIZE / SECTOR_SIZE))) + if (sboff + ps > doff && + sboff < (doff + mddev->dev_sectors + PAGE_SIZE / SECTOR_SIZE)) return -EINVAL; } else if (offset < 0) { /* DATA BITMAP METADATA */ - if (offset - + (long)(page->index * (PAGE_SIZE / SECTOR_SIZE)) - + size / SECTOR_SIZE > 0) + if (offset + ps + size / SECTOR_SIZE > 0) /* bitmap runs in to metadata */ return -EINVAL; - if (rdev->data_offset + mddev->dev_sectors - > rdev->sb_start + offset) + if (doff + mddev->dev_sectors > sboff) /* data runs in to bitmap */ return -EINVAL; } else if (rdev->sb_start < rdev->data_offset) { /* METADATA BITMAP DATA */ - if (rdev->sb_start + offset - + page->index * (PAGE_SIZE / SECTOR_SIZE) - + size / SECTOR_SIZE > rdev->data_offset) + if (sboff + ps + size / SECTOR_SIZE > doff) /* bitmap runs in to data */ return -EINVAL; } else { /* DATA METADATA BITMAP - no problems */ } - md_super_write(mddev, rdev, - rdev->sb_start + offset - + page->index * (PAGE_SIZE / SECTOR_SIZE), - size, page); + md_super_write(mddev, rdev, sboff + ps, (int) size, page); return 0; } -- 2.7.4