From f54478c6e226bb1540a3e58366601039dfd778e2 Mon Sep 17 00:00:00 2001 From: Coly Li Date: Sat, 9 Feb 2019 12:53:00 +0800 Subject: [PATCH] bcache: fix input integer overflow of congested threshold Cache set congested threshold values congested_read_threshold_us and congested_write_threshold_us can be set via sysfs interface. These two values are 'unsigned int' type, but sysfs interface uses strtoul to convert input string. So if people input a large number like 9999999999, the value indeed set is 1410065407, which is not expected behavior. This patch replaces sysfs_strtoul() by sysfs_strtoul_clamp() when convert input string to unsigned int value, and set value range in [0, UINT_MAX], to avoid the above integer overflow errors. Signed-off-by: Coly Li Signed-off-by: Jens Axboe --- drivers/md/bcache/sysfs.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index 9be27b2..bedd3e6 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -778,10 +778,12 @@ STORE(__bch_cache_set) c->shrink.scan_objects(&c->shrink, &sc); } - sysfs_strtoul(congested_read_threshold_us, - c->congested_read_threshold_us); - sysfs_strtoul(congested_write_threshold_us, - c->congested_write_threshold_us); + sysfs_strtoul_clamp(congested_read_threshold_us, + c->congested_read_threshold_us, + 0, UINT_MAX); + sysfs_strtoul_clamp(congested_write_threshold_us, + c->congested_write_threshold_us, + 0, UINT_MAX); if (attr == &sysfs_errors) { v = __sysfs_match_string(error_actions, -1, buf); -- 2.7.4