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| author | Glenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no> | 2016-01-13 16:41:42 +0100 |
|---|---|---|
| committer | Johan Hedberg <johan.hedberg@intel.com> | 2016-01-23 12:21:47 +0000 |
| commit | 4c58f3282e3de43d34f8955f8eca676294380bf9 (patch) | |
| tree | dbb0b1fe7cf4ebe4fe1496bc0d2e0e969ae3eb16 | |
| parent | 00ae40e71d85ea3fed1b906951ffd80e0321a96d (diff) | |
| download | linux-4c58f3282e3de43d34f8955f8eca676294380bf9.tar.gz linux-4c58f3282e3de43d34f8955f8eca676294380bf9.tar.bz2 linux-4c58f3282e3de43d34f8955f8eca676294380bf9.zip | |
Bluetooth: 6lowpan: Fix kernel NULL pointer dereferences
The fixes provided in this patch assigns a valid net_device structure to
skb before dispatching it for further processing.
Scenario #1:
============
Bluetooth 6lowpan receives an uncompressed IPv6 header, and dispatches it
to netif. The following error occurs:
Null pointer dereference error #1 crash log:
[ 845.854013] BUG: unable to handle kernel NULL pointer dereference at
0000000000000048
[ 845.855785] IP: [<ffffffff816e3d36>] enqueue_to_backlog+0x56/0x240
...
[ 845.909459] Call Trace:
[ 845.911678] [<ffffffff816e3f64>] netif_rx_internal+0x44/0xf0
The first modification fixes the NULL pointer dereference error by
assigning dev to the local_skb in order to set a valid net_device before
processing the skb by netif_rx_ni().
Scenario #2:
============
Bluetooth 6lowpan receives an UDP compressed message which needs further
decompression by nhc_udp. The following error occurs:
Null pointer dereference error #2 crash log:
[ 63.295149] BUG: unable to handle kernel NULL pointer dereference at
0000000000000840
[ 63.295931] IP: [<ffffffffc0559540>] udp_uncompress+0x320/0x626
[nhc_udp]
The second modification fixes the NULL pointer dereference error by
assigning dev to the local_skb in the case of a udp compressed packet.
The 6lowpan udp_uncompress function expects that the net_device is set in
the skb when checking lltype.
Signed-off-by: Glenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
Signed-off-by: Lukasz Duda <lukasz.duda@nordicsemi.no>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org # 4.4+
| -rw-r--r-- | net/bluetooth/6lowpan.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index d040365ba98e..58e1b3c97ed7 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -317,6 +317,7 @@ static int recv_pkt(struct sk_buff *skb, struct net_device *dev, local_skb->protocol = htons(ETH_P_IPV6); local_skb->pkt_type = PACKET_HOST; + local_skb->dev = dev; skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); @@ -335,6 +336,8 @@ static int recv_pkt(struct sk_buff *skb, struct net_device *dev, if (!local_skb) goto drop; + local_skb->dev = dev; + ret = iphc_decompress(local_skb, dev, chan); if (ret < 0) { kfree_skb(local_skb); @@ -343,7 +346,6 @@ static int recv_pkt(struct sk_buff *skb, struct net_device *dev, local_skb->protocol = htons(ETH_P_IPV6); local_skb->pkt_type = PACKET_HOST; - local_skb->dev = dev; if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) { |