block: fix SG_[GS]ET_RESERVED_SIZE ioctl when max_sectors is huge (9b4231bf) · Commits · 戴 / test

SG_GET_RESERVED_SIZE and SG_SET_RESERVED_SIZE ioctls access a reserved buffer in bytes as int type. The value needs to be capped at the request queue's max_sectors. But integer overflow is not correctly handled in the calculation when converting max_sectors from sectors to bytes. Signed-off-by:

Akinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: linux-scsi@vger.kernel.org Reviewed-by:

Christoph Hellwig <hch@lst.de> Signed-off-by:

Jens Axboe <axboe@fb.com>

block/scsi_ioctl.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -82,9 +82,18 @@ static int sg_set_timeout(struct request_queue q, int __user p)
		return err;
		}

		static int max_sectors_bytes(struct request_queue *q)
		{
		unsigned int max_sectors = queue_max_sectors(q);

		max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);

		return max_sectors << 9;
		}

		static int sg_get_reserved_size(struct request_queue q, int __user p)
		{
		unsigned val = min(q->sg_reserved_size, queue_max_sectors(q) << 9);
		int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q));

		return put_user(val, p);
		}
		@@ -98,10 +107,8 @@ static int sg_set_reserved_size(struct request_queue q, int __user p)

		if (size < 0)
		return -EINVAL;
		if (size > (queue_max_sectors(q) << 9))
		size = queue_max_sectors(q) << 9;

		q->sg_reserved_size = size;
		q->sg_reserved_size = min(size, max_sectors_bytes(q));
		return 0;
		}

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