Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f1cd14ae authored by Andre Noll's avatar Andre Noll Committed by NeilBrown
Browse files

md: linear: Fix a division by zero bug for very small arrays. 



We currently oops with a divide error on starting a linear software
raid array consisting of at least two very small (< 500K) devices.

The bug is caused by the calculation of the hash table size which
tries to compute sector_div(sz, base) with "base" being zero due to
the small size of the component devices of the array.

Fix this by requiring the hash spacing to be at least one which
implies that also "base" is non-zero.

This bug has existed since about 2.6.14.

Cc: stable@kernel.org
Signed-off-by: default avatarAndre Noll <maan@systemlinux.org>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent a53a6c85

drivers/md/linear.c

+2 −0
Original line number Diff line number Diff line
@@ -148,6 +148,8 @@ static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks) 


	min_sectors = conf->array_sectors;

	sector_div(min_sectors, PAGE_SIZE/sizeof(struct dev_info *));

	if (min_sectors == 0)

		min_sectors = 1;



	/* min_sectors is the minimum spacing that will fit the hash

	 * table in one PAGE.  This may be much smaller than needed.