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authorColy Li <colyli@suse.de>2019-02-09 12:53:10 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-27 09:33:51 +0200
commitd775179e00cdc6fed4c33fef92dcfb24a797e39e (patch)
tree943abc660f7f66b78e0d6390dee7a7afc92bd0c7
parentb25147b49301454409d9e38b0cbd46221be089a8 (diff)
bcache: fix input overflow to cache set sysfs file io_error_halflife
[ 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>
-rw-r--r--drivers/md/bcache/sysfs.c13
1 files 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);