72 lines
2.8 KiB
Diff
72 lines
2.8 KiB
Diff
From: Gerrit Renker <gerrit@erg.abdn.ac.uk>
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Date: Wed, 2 Mar 2011 07:02:07 +0000 (-0800)
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Subject: dccp: fix oops on Reset after close
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X-Git-Tag: v2.6.38-rc8~29^2~9
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X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=720dc34bbbe9493c7bd48b2243058b4e447a929d
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dccp: fix oops on Reset after close
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This fixes a bug in the order of dccp_rcv_state_process() that still permitted
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reception even after closing the socket. A Reset after close thus causes a NULL
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pointer dereference by not preventing operations on an already torn-down socket.
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dccp_v4_do_rcv()
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| state other than OPEN
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v
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dccp_rcv_state_process()
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| DCCP_PKT_RESET
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v
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dccp_rcv_reset()
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v
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dccp_time_wait()
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WARNING: at net/ipv4/inet_timewait_sock.c:141 __inet_twsk_hashdance+0x48/0x128()
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Modules linked in: arc4 ecb carl9170 rt2870sta(C) mac80211 r8712u(C) crc_ccitt ah
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[<c0038850>] (unwind_backtrace+0x0/0xec) from [<c0055364>] (warn_slowpath_common)
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[<c0055364>] (warn_slowpath_common+0x4c/0x64) from [<c0055398>] (warn_slowpath_n)
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[<c0055398>] (warn_slowpath_null+0x1c/0x24) from [<c02b72d0>] (__inet_twsk_hashd)
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[<c02b72d0>] (__inet_twsk_hashdance+0x48/0x128) from [<c031caa0>] (dccp_time_wai)
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[<c031caa0>] (dccp_time_wait+0x40/0xc8) from [<c031c15c>] (dccp_rcv_state_proces)
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[<c031c15c>] (dccp_rcv_state_process+0x120/0x538) from [<c032609c>] (dccp_v4_do_)
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[<c032609c>] (dccp_v4_do_rcv+0x11c/0x14c) from [<c0286594>] (release_sock+0xac/0)
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[<c0286594>] (release_sock+0xac/0x110) from [<c031fd34>] (dccp_close+0x28c/0x380)
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[<c031fd34>] (dccp_close+0x28c/0x380) from [<c02d9a78>] (inet_release+0x64/0x70)
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The fix is by testing the socket state first. Receiving a packet in Closed state
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now also produces the required "No connection" Reset reply of RFC 4340, 8.3.1.
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Reported-and-tested-by: Johan Hovold <jhovold@gmail.com>
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Cc: stable@kernel.org
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Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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---
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diff --git a/net/dccp/input.c b/net/dccp/input.c
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index 8cde009..4222e7a 100644
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--- a/net/dccp/input.c
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+++ b/net/dccp/input.c
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@@ -614,6 +614,9 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
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/* Caller (dccp_v4_do_rcv) will send Reset */
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dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
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return 1;
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+ } else if (sk->sk_state == DCCP_CLOSED) {
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+ dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
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+ return 1;
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}
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if (sk->sk_state != DCCP_REQUESTING && sk->sk_state != DCCP_RESPOND) {
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@@ -668,10 +671,6 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
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}
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switch (sk->sk_state) {
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- case DCCP_CLOSED:
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- dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
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- return 1;
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-
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case DCCP_REQUESTING:
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queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len);
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if (queued >= 0)
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