projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 46eff07a GKH |
1 | From foo@baz Sat Sep 29 04:30:43 PDT 2018 |
| 2 | From: Michael Scott <michael@opensourcefoundries.com> | |
| 3 | Date: Tue, 19 Jun 2018 16:44:06 -0700 | |
| 4 | Subject: 6lowpan: iphc: reset mac_header after decompress to fix panic | |
| 5 | ||
| 6 | From: Michael Scott <michael@opensourcefoundries.com> | |
| 7 | ||
| 8 | [ Upstream commit 03bc05e1a4972f73b4eb8907aa373369e825c252 ] | |
| 9 | ||
| 10 | After decompression of 6lowpan socket data, an IPv6 header is inserted | |
| 11 | before the existing socket payload. After this, we reset the | |
| 12 | network_header value of the skb to account for the difference in payload | |
| 13 | size from prior to decompression + the addition of the IPv6 header. | |
| 14 | ||
| 15 | However, we fail to reset the mac_header value. | |
| 16 | ||
| 17 | Leaving the mac_header value untouched here, can cause a calculation | |
| 18 | error in net/packet/af_packet.c packet_rcv() function when an | |
| 19 | AF_PACKET socket is opened in SOCK_RAW mode for use on a 6lowpan | |
| 20 | interface. | |
| 21 | ||
| 22 | On line 2088, the data pointer is moved backward by the value returned | |
| 23 | from skb_mac_header(). If skb->data is adjusted so that it is before | |
| 24 | the skb->head pointer (which can happen when an old value of mac_header | |
| 25 | is left in place) the kernel generates a panic in net/core/skbuff.c | |
| 26 | line 1717. | |
| 27 | ||
| 28 | This panic can be generated by BLE 6lowpan interfaces (such as bt0) and | |
| 29 | 802.15.4 interfaces (such as lowpan0) as they both use the same 6lowpan | |
| 30 | sources for compression and decompression. | |
| 31 | ||
| 32 | Signed-off-by: Michael Scott <michael@opensourcefoundries.com> | |
| 33 | Acked-by: Alexander Aring <aring@mojatatu.com> | |
| 34 | Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com> | |
| 35 | Signed-off-by: Marcel Holtmann <marcel@holtmann.org> | |
| 36 | Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> | |
| 37 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 38 | --- | |
| 39 | net/6lowpan/iphc.c | 1 + | |
| 40 | 1 file changed, 1 insertion(+) | |
| 41 | ||
| 42 | --- a/net/6lowpan/iphc.c | |
| 43 | +++ b/net/6lowpan/iphc.c | |
| 44 | @@ -569,6 +569,7 @@ int lowpan_header_decompress(struct sk_b | |
| 45 | hdr.hop_limit, &hdr.daddr); | |
| 46 | ||
| 47 | skb_push(skb, sizeof(hdr)); | |
| 48 | + skb_reset_mac_header(skb); | |
| 49 | skb_reset_network_header(skb); | |
| 50 | skb_copy_to_linear_data(skb, &hdr, sizeof(hdr)); | |
| 51 |