mainline inclusion from mainline-5.1-rc1 commit 453745fbbebecf7e459785db7e29e11563908525 category: backport 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> --- drivers/md/bcache/sysfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index c6869d80adf1..48234481cd50 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -835,7 +835,9 @@ 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); -- 2.16.4