Commit dab71b2d authored Feb 09, 2019 by Coly Li Committed by Jens Axboe Feb 09, 2019

bcache: fix input overflow to writeback_rate_minimum



dc->writeback_rate_minimum is type unsigned integer variable, it is set
via sysfs interface, and converte from input string to unsigned integer
by d_strtoul_nonzero(). When the converted input value is larger than
UINT_MAX, overflow to unsigned integer happens.

This patch fixes the overflow by using sysfs_strotoul_clamp() to
convert input string and limit the value in range [1, UINT_MAX], then
the overflow can be avoided.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 5b5fd3c9

drivers/md/bcache/sysfs.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -308,7 +308,9 @@ STORE(__cached_dev)
		sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
		dc->writeback_rate_p_term_inverse,
		1, UINT_MAX);
		d_strtoul_nonzero(writeback_rate_minimum);
		sysfs_strtoul_clamp(writeback_rate_minimum,
		dc->writeback_rate_minimum,
		1, UINT_MAX);

		sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX);

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