4.9-stable review patch. If anyone has any objections, please let me know.
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[ 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 colyli@suse.de Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@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 87daccbbc61b..463ce6757338 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -215,7 +215,9 @@ STORE(__cached_dev) d_strtoul(writeback_rate_d_term); d_strtoul_nonzero(writeback_rate_p_term_inverse);
- 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)