| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.15 123/124] block/compat_ioctl: fix range check in BLKGETSIZE | Date | Tue, 26 Apr 2022 10:22:04 +0200 |
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From: Khazhismel Kumykov <khazhy@google.com>
commit ccf16413e520164eb718cf8b22a30438da80ff23 upstream.
kernel ulong and compat_ulong_t may not be same width. Use type directly to eliminate mismatches.
This would result in truncation rather than EFBIG for 32bit mode for large disks.
Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Khazhismel Kumykov <khazhy@google.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220414224056.2875681-1-khazhy@google.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- block/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/block/ioctl.c +++ b/block/ioctl.c @@ -645,7 +645,7 @@ long compat_blkdev_ioctl(struct file *fi (bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512); case BLKGETSIZE: size = i_size_read(bdev->bd_inode); - if ((size >> 9) > ~0UL) + if ((size >> 9) > ~(compat_ulong_t)0) return -EFBIG; return compat_put_ulong(argp, size >> 9);
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