From: Coly Li <col...@suse.de>
[ Upstream commit 8c27a3953e92eb0b22dbb03d599f543a05f9574e ]
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 <col...@suse.de>
Signed-off-by: Jens Axboe <ax...@kernel.dk>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
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 3b287f974fd9..f98cda32065d 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -299,7 +299,9 @@ 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)
--
2.19.1
