This is a note to let you know that I've just added the patch titled
mac80211: fix potential overflow when multiplying to u32 integers
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mac80211-fix-potential-overflow-when-multiplying-to-.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit da4c0942b1cb55fd4a2baa494b3ff9a934b8bc02
Author: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Date: Fri Feb 5 17:53:52 2021 +0000
mac80211: fix potential overflow when multiplying to u32 integers
[ 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@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210205175352.208841-1-colin.king@xxxxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index aa5150929996d..b5b728a71ab53 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -356,7 +356,7 @@ 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;
}
