This is a note to let you know that I've just added the patch titled
net: Fix unwanted sign extension in netdev_stats_to_stats64()
to the 4.19-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:
net-fix-unwanted-sign-extension-in-netdev_stats_to_s.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit adc3a55bb14544428f4a5eedcedb39d200f58685
Author: Felix Riemann <felix.riemann@xxxxxx>
Date: Fri Feb 10 13:36:44 2023 +0100
net: Fix unwanted sign extension in netdev_stats_to_stats64()
[ Upstream commit 9b55d3f0a69af649c62cbc2633e6d695bb3cc583 ]
When converting net_device_stats to rtnl_link_stats64 sign extension
is triggered on ILP32 machines as 6c1c509778 changed the previous
"ulong -> u64" conversion to "long -> u64" by accessing the
net_device_stats fields through a (signed) atomic_long_t.
This causes for example the received bytes counter to jump to 16EiB after
having received 2^31 bytes. Casting the atomic value to "unsigned long"
beforehand converting it into u64 avoids this.
Fixes: 6c1c5097781f ("net: add atomic_long_t to net_device_stats fields")
Signed-off-by: Felix Riemann <felix.riemann@xxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/dev.c b/net/core/dev.c
index 3bf40c288c032..0f9214fb36e01 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9041,7 +9041,7 @@ void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
for (i = 0; i < n; i++)
- dst[i] = atomic_long_read(&src[i]);
+ dst[i] = (unsigned long)atomic_long_read(&src[i]);
/* zero out counters that only exist in rtnl_link_stats64 */
memset((char *)stats64 + n * sizeof(u64), 0,
sizeof(*stats64) - n * sizeof(u64));
