netdev - [PATCH net-next 4/7] r8169: improve rtl_coalesce_choose

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <15ec315a-724b-e4ba-83ad-9df424307fa4@gmail.com>
Date:   Thu, 30 Apr 2020 21:57:32 +0200
From:   Heiner Kallweit <hkallweit1@...il.com>
To:     Realtek linux nic maintainers <nic_swsd@...ltek.com>,
        David Miller <davem@...emloft.net>
Cc:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: [PATCH net-next 4/7] r8169: improve rtl_coalesce_choose_scale

The time limit provided by userspace is multiplied with 1000,
what could result in an overflow. Therefore change the time limit
parameter unit from ns to us, and avoid the problematic operation.
If there's no matching scale because provided time limit is too big,
return ERANGE instead of EINVAL to provide a hint to the user what's
wrong.

Signed-off-by: Heiner Kallweit <hkallweit1@...il.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index d898e6f5f..a95615684 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -1854,8 +1854,8 @@ static int rtl_get_coalesce(struct net_device *dev, struct ethtool_coalesce *ec)
 	return 0;
 }
 
-/* choose appropriate scale factor and CPlusCmd[0:1] for (speed, nsec) */
-static int rtl_coalesce_choose_scale(struct rtl8169_private *tp, u32 nsec,
+/* choose appropriate scale factor and CPlusCmd[0:1] for (speed, usec) */
+static int rtl_coalesce_choose_scale(struct rtl8169_private *tp, u32 usec,
 				     u16 *cp01)
 {
 	const struct rtl_coalesce_info *ci;
@@ -1866,13 +1866,13 @@ static int rtl_coalesce_choose_scale(struct rtl8169_private *tp, u32 nsec,
 		return PTR_ERR(ci);
 
 	for (i = 0; i < 4; i++) {
-		if (nsec <= ci->scale_nsecs[i] * RTL_COALESCE_T_MAX) {
+		if (usec <= ci->scale_nsecs[i] * RTL_COALESCE_T_MAX / 1000U) {
 			*cp01 = i;
 			return ci->scale_nsecs[i];
 		}
 	}
 
-	return -EINVAL;
+	return -ERANGE;
 }
 
 static int rtl_set_coalesce(struct net_device *dev, struct ethtool_coalesce *ec)
@@ -1886,13 +1886,14 @@ static int rtl_set_coalesce(struct net_device *dev, struct ethtool_coalesce *ec)
 		{ ec->tx_max_coalesced_frames, ec->tx_coalesce_usecs }
 	}, *p = coal_settings;
 	u16 w = 0, cp01 = 0;
+	u32 coal_usec_max;
 	int scale, i;
 
 	if (rtl_is_8125(tp))
 		return -EOPNOTSUPP;
 
-	scale = rtl_coalesce_choose_scale(tp,
-			max(p[0].usecs, p[1].usecs) * 1000, &cp01);
+	coal_usec_max = max(ec->rx_coalesce_usecs, ec->tx_coalesce_usecs);
+	scale = rtl_coalesce_choose_scale(tp, coal_usec_max, &cp01);
 	if (scale < 0)
 		return scale;
 
-- 
2.26.2