From: Michal Kubecek mkubecek@suse.cz
[ Upstream commit efb796f5571f030743e1d9c662cdebdad724f8c5 ]
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 mkubecek@suse.cz Link: https://lore.kernel.org/r/b54ed5c5fd972a59afea3e1badfb36d86df68799.160795220... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ethtool/strset.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ethtool/strset.c +++ b/net/ethtool/strset.c @@ -182,7 +182,7 @@ static int strset_parse_request(struct e 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;