From: Colin Ian King colin.king@canonical.com
[ Upstream commit 6194f7e6473be78acdc5d03edd116944bdbb2c4e ]
The multiplication of the u32 variables tx_time and estimated_retx is performed using a 32 bit multiplication and the result is stored in a u64 result. This has a potential u32 overflow issue, so avoid this by casting tx_time to a u64 to force a 64 bit multiply.
Addresses-Coverity: ("Unintentional integer overflow") Fixes: 050ac52cbe1f ("mac80211: code for on-demand Hybrid Wireless Mesh Protocol") Signed-off-by: Colin Ian King colin.king@canonical.com Link: https://lore.kernel.org/r/20210205175352.208841-1-colin.king@canonical.com Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac80211/mesh_hwmp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index 6219b6b0c7e17..18158855d98c4 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -355,7 +355,7 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local, */ tx_time = (device_constant + 10 * test_frame_len / rate); estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); - result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT); + result = ((u64)tx_time * estimated_retx) >> (2 * ARITH_SHIFT); return (u32)result; }