bcache: fix input overflow to sequential_cutoff

People may set sequential_cutoff of a cached device via sysfs file,
but current code does not check input value overflow. E.g. if value
4294967295 (UINT_MAX) is written to file sequential_cutoff, its value
is 4GB, but if 4294967296 (UINT_MAX + 1) is written into, its value
will be 0. This is an unexpected behavior.

This patch replaces d_strtoi_h() by sysfs_strtoul_clamp() to convert
input string to unsigned integer value, and limit its range in
[0, UINT_MAX]. Then the input overflow can be fixed.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Coly Li 2019-02-09 12:53:01 +08:00 committed by Jens Axboe
parent f54478c6e2
commit 8c27a3953e
1 changed files with 3 additions and 1 deletions

View File

@ -314,7 +314,9 @@ STORE(__cached_dev)
dc->io_disable = v ? 1 : 0;
}
d_strtoi_h(sequential_cutoff);
sysfs_strtoul_clamp(sequential_cutoff,
dc->sequential_cutoff,
0, UINT_MAX);
d_strtoi_h(readahead);
if (attr == &sysfs_clear_stats)