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authorColy Li <colyli@suse.de>2019-02-09 12:53:10 +0800
committerJens Axboe <axboe@kernel.dk>2019-02-09 07:18:33 -0700
commita91fbda49f746119828f7e8ad0f0aa2ab0578f65 (patch)
tree146a7c1d8048648530d36fd11ec0e31a1557373f /drivers/md
parentb15008403b59955c9fa0c8b55cadd6dae991a4e9 (diff)
bcache: fix input overflow to cache set sysfs file io_error_halflife
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>
Diffstat (limited to 'drivers/md')
-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 467105614324..17bae9c14ca0 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -804,8 +804,17 @@ STORE(__bch_cache_set)
sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX);
/* 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;
+ }
if (attr == &sysfs_io_disable) {
v = strtoul_or_return(buf);