From 697ba0b6ec4ae04afb67d3911799b5e2043b4455 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Tue, 3 Sep 2024 22:48:19 +0300 Subject: [PATCH] block: fix integer overflow in BLKSECDISCARD I independently rediscovered commit 22d24a544b0d49bbcbd61c8c0eaf77d3c9297155 block: fix overflow in blk_ioctl_discard() but for secure erase. Same problem: uint64_t r[2] = {512, 18446744073709551104ULL}; ioctl(fd, BLKSECDISCARD, r); will enter near infinite loop inside blkdev_issue_secure_erase(): a.out: attempt to access beyond end of device loop0: rw=5, sector=3399043073, nr_sectors = 1024 limit=2048 bio_check_eod: 3286214 callbacks suppressed Signed-off-by: Alexey Dobriyan Link: https://lore.kernel.org/r/9e64057f-650a-46d1-b9f7-34af391536ef@p183 Signed-off-by: Jens Axboe --- block/ioctl.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index e8e4a4190f18..44257bdfeacb 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -126,7 +126,7 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, return -EINVAL; filemap_invalidate_lock(bdev->bd_mapping); - err = truncate_bdev_range(bdev, mode, start, start + len - 1); + err = truncate_bdev_range(bdev, mode, start, end - 1); if (err) goto fail; @@ -163,7 +163,7 @@ fail: static int blk_ioctl_secure_erase(struct block_device *bdev, blk_mode_t mode, void __user *argp) { - uint64_t start, len; + uint64_t start, len, end; uint64_t range[2]; int err; @@ -178,11 +178,12 @@ static int blk_ioctl_secure_erase(struct block_device *bdev, blk_mode_t mode, len = range[1]; if ((start & 511) || (len & 511)) return -EINVAL; - if (start + len > bdev_nr_bytes(bdev)) + if (check_add_overflow(start, len, &end) || + end > bdev_nr_bytes(bdev)) return -EINVAL; filemap_invalidate_lock(bdev->bd_mapping); - err = truncate_bdev_range(bdev, mode, start, start + len - 1); + err = truncate_bdev_range(bdev, mode, start, end - 1); if (!err) err = blkdev_issue_secure_erase(bdev, start >> 9, len >> 9, GFP_KERNEL);