path: root/net
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authorGerrit Renker <gerrit@erg.abdn.ac.uk>2011-03-01 23:02:07 -0800
committerDavid S. Miller <davem@davemloft.net>2011-03-01 23:02:07 -0800
commit720dc34bbbe9493c7bd48b2243058b4e447a929d (patch)
tree1c99c2d5018e2cfc7f4eb6721f57d5ae144abb56 /net
parent6ea25a6c2b95cf916e844fe2bacdd1c15b72e4c5 (diff)
dccp: fix oops on Reset after close
This fixes a bug in the order of dccp_rcv_state_process() that still permitted reception even after closing the socket. A Reset after close thus causes a NULL pointer dereference by not preventing operations on an already torn-down socket. dccp_v4_do_rcv() | | state other than OPEN v dccp_rcv_state_process() | | DCCP_PKT_RESET v dccp_rcv_reset() | v dccp_time_wait() WARNING: at net/ipv4/inet_timewait_sock.c:141 __inet_twsk_hashdance+0x48/0x128() Modules linked in: arc4 ecb carl9170 rt2870sta(C) mac80211 r8712u(C) crc_ccitt ah [<c0038850>] (unwind_backtrace+0x0/0xec) from [<c0055364>] (warn_slowpath_common) [<c0055364>] (warn_slowpath_common+0x4c/0x64) from [<c0055398>] (warn_slowpath_n) [<c0055398>] (warn_slowpath_null+0x1c/0x24) from [<c02b72d0>] (__inet_twsk_hashd) [<c02b72d0>] (__inet_twsk_hashdance+0x48/0x128) from [<c031caa0>] (dccp_time_wai) [<c031caa0>] (dccp_time_wait+0x40/0xc8) from [<c031c15c>] (dccp_rcv_state_proces) [<c031c15c>] (dccp_rcv_state_process+0x120/0x538) from [<c032609c>] (dccp_v4_do_) [<c032609c>] (dccp_v4_do_rcv+0x11c/0x14c) from [<c0286594>] (release_sock+0xac/0) [<c0286594>] (release_sock+0xac/0x110) from [<c031fd34>] (dccp_close+0x28c/0x380) [<c031fd34>] (dccp_close+0x28c/0x380) from [<c02d9a78>] (inet_release+0x64/0x70) The fix is by testing the socket state first. Receiving a packet in Closed state now also produces the required "No connection" Reset reply of RFC 4340, 8.3.1. Reported-and-tested-by: Johan Hovold <jhovold@gmail.com> Cc: stable@kernel.org Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 3 insertions, 4 deletions
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 8cde009e8b85..4222e7a654b0 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -614,6 +614,9 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
/* Caller (dccp_v4_do_rcv) will send Reset */
dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
return 1;
+ } else if (sk->sk_state == DCCP_CLOSED) {
+ dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
+ return 1;
if (sk->sk_state != DCCP_REQUESTING && sk->sk_state != DCCP_RESPOND) {
@@ -668,10 +671,6 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
switch (sk->sk_state) {
- dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
- return 1;
queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len);
if (queued >= 0)