From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Xie He <xie.he.0141@gmail.com>,
"David S . Miller" <davem@davemloft.net>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.4 6/9] drivers/net/wan/lapbether: Fixed the value of hard_header_len
Date: Tue, 14 Jul 2020 10:40:20 -0400 [thread overview]
Message-ID: <20200714144024.4036118-6-sashal@kernel.org> (raw)
In-Reply-To: <20200714144024.4036118-1-sashal@kernel.org>
From: Xie He <xie.he.0141@gmail.com>
[ Upstream commit 9dc829a135fb5927f1519de11286e2bbb79f5b66 ]
When this driver transmits data,
first this driver will remove a pseudo header of 1 byte,
then the lapb module will prepend the LAPB header of 2 or 3 bytes,
then this driver will prepend a length field of 2 bytes,
then the underlying Ethernet device will prepend its own header.
So, the header length required should be:
-1 + 3 + 2 + "the header length needed by the underlying device".
This patch fixes kernel panic when this driver is used with AF_PACKET
SOCK_DGRAM sockets.
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wan/lapbether.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c
index 6676607164d65..f5657783fad4e 100644
--- a/drivers/net/wan/lapbether.c
+++ b/drivers/net/wan/lapbether.c
@@ -308,7 +308,6 @@ static void lapbeth_setup(struct net_device *dev)
dev->netdev_ops = &lapbeth_netdev_ops;
dev->destructor = free_netdev;
dev->type = ARPHRD_X25;
- dev->hard_header_len = 3;
dev->mtu = 1000;
dev->addr_len = 0;
}
@@ -329,6 +328,14 @@ static int lapbeth_new_device(struct net_device *dev)
if (!ndev)
goto out;
+ /* When transmitting data:
+ * first this driver removes a pseudo header of 1 byte,
+ * then the lapb module prepends an LAPB header of at most 3 bytes,
+ * then this driver prepends a length field of 2 bytes,
+ * then the underlying Ethernet device prepends its own header.
+ */
+ ndev->hard_header_len = -1 + 3 + 2 + dev->hard_header_len;
+
lapbeth = netdev_priv(ndev);
lapbeth->axdev = ndev;
--
2.25.1
next prev parent reply other threads:[~2020-07-14 14:40 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 14:40 [PATCH AUTOSEL 4.4 1/9] pinctrl: amd: fix npins for uart0 in kerncz_groups Sasha Levin
2020-07-14 14:40 ` [PATCH AUTOSEL 4.4 2/9] mac80211: allow rx of mesh eapol frames with default rx key Sasha Levin
2020-07-14 14:40 ` [PATCH AUTOSEL 4.4 3/9] scsi: scsi_transport_spi: Fix function pointer check Sasha Levin
2020-07-14 14:40 ` [PATCH AUTOSEL 4.4 4/9] xtensa: fix __sync_fetch_and_{and,or}_4 declarations Sasha Levin
2020-07-14 14:40 ` [PATCH AUTOSEL 4.4 5/9] xtensa: update *pos in cpuinfo_op.next Sasha Levin
2020-07-14 14:40 ` Sasha Levin [this message]
2020-07-14 14:40 ` [PATCH AUTOSEL 4.4 7/9] ALSA: hda/hdmi: fix failures at PCM open on Intel ICL and later Sasha Levin
2020-07-15 10:52 ` Kai Vehmanen
2020-07-22 13:48 ` Sasha Levin
2020-07-14 14:40 ` [PATCH AUTOSEL 4.4 8/9] net: sky2: initialize return of gm_phy_read Sasha Levin
2020-07-14 14:40 ` [PATCH AUTOSEL 4.4 9/9] drm/nouveau/i2c/g94-: increase NV_PMGR_DP_AUXCTL_TRANSACTREQ timeout Sasha Levin
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