From: Johannes Thumshirn <[email protected]> commit a9cb9f4148ef6bb8fabbdaa85c42b2171fbd5a0d upstream.
Don't call report zones for more zones than the user actually requested, otherwise this can lead to out-of-bounds accesses in the callback functions. Such a situation can happen if the target's ->report_zones() callback function returns 0 because we've reached the end of the target and then restart the report zones on the second target. We're again calling into ->report_zones() and ultimately into the user supplied callback function but when we're not subtracting the number of zones already processed this may lead to out-of-bounds accesses in the user callbacks. Signed-off-by: Johannes Thumshirn <[email protected]> Reviewed-by: Damien Le Moal <[email protected]> Fixes: d41003513e61 ("block: rework zone reporting") Cc: [email protected] # v5.5+ Signed-off-by: Mike Snitzer <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/md/dm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -504,7 +504,8 @@ static int dm_blk_report_zones(struct ge } args.tgt = tgt; - ret = tgt->type->report_zones(tgt, &args, nr_zones); + ret = tgt->type->report_zones(tgt, &args, + nr_zones - args.zone_idx); if (ret < 0) goto out; } while (args.zone_idx < nr_zones &&
