Commit 453745fb authored Feb 09, 2019 by Coly Li Committed by Jens Axboe Feb 09, 2019

bcache: fix input overflow to journal_delay_ms



c->journal_delay_ms is in type unsigned short, it is set via sysfs
interface and converted by sysfs_strtoul() from input string to
unsigned short value. Therefore overflow to unsigned short might be
happen when the converted value exceed USHRT_MAX. e.g. writing
65536 into sysfs file journal_delay_ms, c->journal_delay_ms is set to
0.

This patch uses sysfs_strtoul_clamp() to convert the input string and
limit value range in [0, USHRT_MAX], to avoid the input overflow.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent dab71b2d

drivers/md/bcache/sysfs.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -821,7 +821,9 @@ STORE(__bch_cache_set)
		}
		}

		sysfs_strtoul(journal_delay_ms, c->journal_delay_ms);
		sysfs_strtoul_clamp(journal_delay_ms,
		c->journal_delay_ms,
		0, USHRT_MAX);
		sysfs_strtoul_bool(verify, c->verify);
		sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled);
		sysfs_strtoul(expensive_debug_checks, c->expensive_debug_checks);

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