From efb796f5571f030743e1d9c662cdebdad724f8c5 Mon Sep 17 00:00:00 2001 From: Michal Kubecek Date: Mon, 14 Dec 2020 14:25:01 +0100 Subject: ethtool: fix string set id check Syzbot reported a shift of a u32 by more than 31 in strset_parse_request() which is undefined behavior. This is caused by range check of string set id using variable ret (which is always 0 at this point) instead of id (string set id from request). Fixes: 71921690f974 ("ethtool: provide string sets with STRSET_GET request") Reported-by: syzbot+96523fb438937cd01220@syzkaller.appspotmail.com Signed-off-by: Michal Kubecek Link: https://lore.kernel.org/r/b54ed5c5fd972a59afea3e1badfb36d86df68799.1607952208.git.mkubecek@suse.cz Signed-off-by: Jakub Kicinski --- net/ethtool/strset.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c index 0baad0ce1832..c3a5489964cd 100644 --- a/net/ethtool/strset.c +++ b/net/ethtool/strset.c @@ -182,7 +182,7 @@ static int strset_parse_request(struct ethnl_req_info *req_base, ret = strset_get_id(attr, &id, extack); if (ret < 0) return ret; - if (ret >= ETH_SS_COUNT) { + if (id >= ETH_SS_COUNT) { NL_SET_ERR_MSG_ATTR(extack, attr, "unknown string set id"); return -EOPNOTSUPP; -- cgit v1.2.3-59-g8ed1b