Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 3.18 24/41] bcache: fix input overflow to cache set sysfs file io_error_halflife | Date | Wed, 27 Mar 2019 14:25:01 -0400 |
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From: Coly Li <colyli@suse.de>
[ Upstream commit a91fbda49f746119828f7e8ad0f0aa2ab0578f65 ]
Cache set sysfs entry io_error_halflife is used to set c->error_decay. c->error_decay is in type unsigned int, and it is converted by strtoul_or_return(), therefore overflow to c->error_decay is possible for a large input value.
This patch fixes the overflow by using strtoul_safe_clamp() to convert input string to an unsigned long value in range [0, UINT_MAX], then divides by 88 and set it to c->error_decay.
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 | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index 5a5c1f1bd8a5..87daccbbc61b 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -645,8 +645,17 @@ STORE(__bch_cache_set) c->error_limit = strtoul_or_return(buf) << IO_ERROR_SHIFT; /* See count_io_errors() for why 88 */ - if (attr == &sysfs_io_error_halflife) - c->error_decay = strtoul_or_return(buf) / 88; + if (attr == &sysfs_io_error_halflife) { + unsigned long v = 0; + ssize_t ret; + + ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX); + if (!ret) { + c->error_decay = v / 88; + return size; + } + return ret; + } sysfs_strtoul(journal_delay_ms, c->journal_delay_ms); sysfs_strtoul(verify, c->verify); -- 2.19.1
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