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authorGlenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>2016-01-13 16:41:42 +0100
committerJohan Hedberg <johan.hedberg@intel.com>2016-01-23 12:21:47 +0000
commit4c58f3282e3de43d34f8955f8eca676294380bf9 (patch)
treedbb0b1fe7cf4ebe4fe1496bc0d2e0e969ae3eb16 /net
parent00ae40e71d85ea3fed1b906951ffd80e0321a96d (diff)
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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+
Diffstat (limited to 'net')
-rw-r--r--net/bluetooth/6lowpan.c4
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) {