diff options
| author | Jacob Wen <jian.w.wen@oracle.com> | 2019-01-30 14:55:14 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-06 19:43:06 +0100 |
| commit | 245426dc30affbdfd0488f85014e25340e3004ee (patch) | |
| tree | 5170b42a9cc0267ebfb3318fa9d42096b432f6a1 /net/l2tp/l2tp_ip6.c | |
| parent | f5f5d316fa2959cd2bd85e61ff50d0a68cd885a8 (diff) | |
l2tp: fix reading optional fields of L2TPv3
[ Upstream commit 4522a70db7aa5e77526a4079628578599821b193 ]
Use pskb_may_pull() to make sure the optional fields are in skb linear
parts, so we can safely read them later.
It's easy to reproduce the issue with a net driver that supports paged
skb data. Just create a L2TPv3 over IP tunnel and then generates some
network traffic.
Once reproduced, rx err in /sys/kernel/debug/l2tp/tunnels will increase.
Changes in v4:
1. s/l2tp_v3_pull_opt/l2tp_v3_ensure_opt_in_linear/
2. s/tunnel->version != L2TP_HDR_VER_2/tunnel->version == L2TP_HDR_VER_3/
3. Add 'Fixes' in commit messages.
Changes in v3:
1. To keep consistency, move the code out of l2tp_recv_common.
2. Use "net" instead of "net-next", since this is a bug fix.
Changes in v2:
1. Only fix L2TPv3 to make code simple.
To fix both L2TPv3 and L2TPv2, we'd better refactor l2tp_recv_common.
It's complicated to do so.
2. Reloading pointers after pskb_may_pull
Fixes: f7faffa3ff8e ("l2tp: Add L2TPv3 protocol support")
Fixes: 0d76751fad77 ("l2tp: Add L2TPv3 IP encapsulation (no UDP) support")
Fixes: a32e0eec7042 ("l2tp: introduce L2TPv3 IP encapsulation support for IPv6")
Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/l2tp/l2tp_ip6.c')
| -rw-r--r-- | net/l2tp/l2tp_ip6.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c index 591d308bf63a..e066111b9398 100644 --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -174,6 +174,9 @@ static int l2tp_ip6_recv(struct sk_buff *skb) print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); } + if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) + goto discard; + l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook); return 0; |