From: Jia-Ju Bai baijiaju1990@gmail.com
[ Upstream commit b55f3b841099e641bdb2701d361a4c304e2dbd6f ]
In hwsim_dump_radio_nl(), when genlmsg_put() on line 3617 fails, hdr is assigned to NULL. Then hdr is used on lines 3622 and 3623: genl_dump_check_consistent(cb, hdr); genlmsg_end(skb, hdr);
Thus, possible null-pointer dereferences may occur.
To fix these bugs, hdr is used here when it is not NULL.
This bug is found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai baijiaju1990@gmail.com Link: https://lore.kernel.org/r/20190729082332.28895-1-baijiaju1990@gmail.com [put braces on all branches] Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/mac80211_hwsim.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 1c699a9fa8661..faec05ab42754 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3615,10 +3615,12 @@ static int hwsim_dump_radio_nl(struct sk_buff *skb, hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, &hwsim_genl_family, NLM_F_MULTI, HWSIM_CMD_GET_RADIO); - if (!hdr) + if (hdr) { + genl_dump_check_consistent(cb, hdr); + genlmsg_end(skb, hdr); + } else { res = -EMSGSIZE; - genl_dump_check_consistent(cb, hdr); - genlmsg_end(skb, hdr); + } }
done: