From a91fbda49f746119828f7e8ad0f0aa2ab0578f65 Mon Sep 17 00:00:00 2001 From: Coly Li Date: Sat, 9 Feb 2019 12:53:10 +0800 Subject: bcache: fix input overflow to cache set sysfs file io_error_halflife Cache set sysfs entry io_error_halflife is used to set c->error_decay. c->error_decay is in type unsigned int, and it is converted by strtoul_or_return(), therefore overflow to c->error_decay is possible for a large input value. This patch fixes the overflow by using strtoul_safe_clamp() to convert input string to an unsigned long value in range [0, UINT_MAX], then divides by 88 and set it to c->error_decay. Signed-off-by: Coly Li Signed-off-by: Jens Axboe --- drivers/md/bcache/sysfs.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index 467105614324..17bae9c14ca0 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -804,8 +804,17 @@ STORE(__bch_cache_set) sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX); /* See count_io_errors() for why 88 */ - if (attr == &sysfs_io_error_halflife) - c->error_decay = strtoul_or_return(buf) / 88; + if (attr == &sysfs_io_error_halflife) { + unsigned long v = 0; + ssize_t ret; + + ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX); + if (!ret) { + c->error_decay = v / 88; + return size; + } + return ret; + } if (attr == &sysfs_io_disable) { v = strtoul_or_return(buf); -- cgit