linux/drivers/md/bcache
Coly Li c3b75a2199 bcache: fix potential div-zero error of writeback_rate_i_term_inverse
dc->writeback_rate_i_term_inverse can be set via sysfs interface. It is
in type unsigned int, and convert from input string by d_strtoul(). The
problem is d_strtoul() does not check valid range of the input, if
4294967296 is written into sysfs file writeback_rate_i_term_inverse,
an overflow of unsigned integer will happen and value 0 is set to
dc->writeback_rate_i_term_inverse.

In writeback.c:__update_writeback_rate(), there are following lines of
code,
      integral_scaled = div_s64(dc->writeback_rate_integral,
                      dc->writeback_rate_i_term_inverse);
If dc->writeback_rate_i_term_inverse is set to 0 via sysfs interface,
a div-zero error might be triggered in the above code.

Therefore we need to add a range limitation in the sysfs interface,
this is what this patch does, use sysfs_stroul_clamp() to replace
d_strtoul() and restrict the input range in [1, UINT_MAX].

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-09 07:18:32 -07:00
..
alloc.c bcache: use MAX_CACHES_PER_SET instead of magic number 8 in __bch_bucket_alloc_set 2018-10-08 08:19:56 -06:00
bcache.h bcache: option to automatically run gc thread after writeback 2018-12-13 08:15:54 -07:00
bset.c bcache: fix code comments style 2018-08-11 15:46:42 -06:00
bset.h bcache: style fixes for lines over 80 characters 2018-08-11 15:46:41 -06:00
btree.c bcache: add comment for cache_set->fill_iter 2018-12-13 08:15:54 -07:00
btree.h bcache: introduce force_wake_up_gc() 2018-12-13 08:15:54 -07:00
closure.c bcache: add missing SPDX header 2018-08-11 15:46:42 -06:00
closure.h bcache: fix typo in code comments of closure_return_with_destructor() 2018-10-08 08:19:43 -06:00
debug.c bcache: do not check if debug dentry is ERR or NULL explicitly on remove 2018-12-13 08:15:54 -07:00
debug.h bcache: add identifier names to arguments of function definitions 2018-08-11 15:46:41 -06:00
extents.c bcache: treat stale && dirty keys as bad keys 2019-02-09 07:18:31 -07:00
extents.h bcache: add identifier names to arguments of function definitions 2018-08-11 15:46:41 -06:00
io.c bcache: fix typo 'succesfully' to 'successfully' 2018-08-11 15:46:42 -06:00
journal.c bcache: print number of keys in trace_bcache_journal_write 2018-12-13 08:15:54 -07:00
journal.h bcache: add identifier names to arguments of function definitions 2018-08-11 15:46:41 -06:00
Kconfig for-4.19/post-20180822 2018-08-22 13:38:05 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
movinggc.c bcache: style fix to add a blank line after declarations 2018-08-11 15:46:41 -06:00
request.c bcache: update comment for bch_data_insert 2018-12-13 08:15:54 -07:00
request.h bcache: remove unused bch_passthrough_cache 2018-10-08 08:19:52 -06:00
stats.c bcache: not use hard coded memset size in bch_cache_accounting_clear() 2019-02-09 07:18:31 -07:00
stats.h bcache: add identifier names to arguments of function definitions 2018-08-11 15:46:41 -06:00
super.c bcache: fix indentation issue, remove tabs on a hunk of code 2019-02-09 07:18:31 -07:00
sysfs.c bcache: fix potential div-zero error of writeback_rate_i_term_inverse 2019-02-09 07:18:32 -07:00
sysfs.h bcache: add sysfs_strtoul_bool() for setting bit-field variables 2019-02-09 07:18:32 -07:00
trace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
util.c for-4.19/post-20180822 2018-08-22 13:38:05 -07:00
util.h for-4.19/post-20180822 2018-08-22 13:38:05 -07:00
writeback.c bcache: option to automatically run gc thread after writeback 2018-12-13 08:15:54 -07:00
writeback.h bcache: never writeback a discard operation 2019-02-09 07:18:31 -07:00