diff mbox series

[iptables,v2] libxt_sctp: fix array out of range in print_chunk

Message ID 20171113132754.14911-1-nicolas.dichtel@6wind.com
State Accepted
Delegated to: Pablo Neira
Headers show
Series [iptables,v2] libxt_sctp: fix array out of range in print_chunk | expand

Commit Message

Nicolas Dichtel Nov. 13, 2017, 1:27 p.m. UTC 
From: huaibin Wang <huaibin.wang@6wind.com>

For chunk type ASCONF, ASCONF_ACK and FORWARD_TSN, sctp_chunk_names[].chunk_type
is not equal to the corresponding index in sctp_chunk_names[]. Using this field
leads to a segmentation fault (index out of range).

Example
$ iptables -A INPUT -p sctp --chunk-type all ASCONF,ASCONF_ACK,FORWARD_TSN -j ACCEPT
$ iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
Segmentation fault

Signed-off-by: huaibin Wang <huaibin.wang@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
---

v1 -> v2:
 uncomment corresponding tests

 extensions/libxt_sctp.c | 2 +-
 extensions/libxt_sctp.t | 9 +++------
 2 files changed, 4 insertions(+), 7 deletions(-)

Comments

Pablo Neira Ayuso Nov. 13, 2017, 1:29 p.m. UTC | #1 
On Mon, Nov 13, 2017 at 02:27:54PM +0100, Nicolas Dichtel wrote:
> From: huaibin Wang <huaibin.wang@6wind.com>
> 
> For chunk type ASCONF, ASCONF_ACK and FORWARD_TSN, sctp_chunk_names[].chunk_type
> is not equal to the corresponding index in sctp_chunk_names[]. Using this field
> leads to a segmentation fault (index out of range).
> 
> Example
> $ iptables -A INPUT -p sctp --chunk-type all ASCONF,ASCONF_ACK,FORWARD_TSN -j ACCEPT
> $ iptables -L
> Chain INPUT (policy ACCEPT)
> target     prot opt source               destination
> Segmentation fault

Applied, thanks a lot Nicolas.
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diff mbox series

Patch

diff --git a/extensions/libxt_sctp.c b/extensions/libxt_sctp.c
index df1936be8b83..140de2653b1e 100644
--- a/extensions/libxt_sctp.c
+++ b/extensions/libxt_sctp.c
@@ -370,7 +370,7 @@  print_chunk(uint32_t chunknum, int numeric)
 
 		for (i = 0; i < ARRAY_SIZE(sctp_chunk_names); ++i)
 			if (sctp_chunk_names[i].chunk_type == chunknum)
-				printf("%s", sctp_chunk_names[chunknum].name);
+				printf("%s", sctp_chunk_names[i].name);
 	}
 }
 
diff --git a/extensions/libxt_sctp.t b/extensions/libxt_sctp.t
index 2f75e2a68e8e..4016e4fb1880 100644
--- a/extensions/libxt_sctp.t
+++ b/extensions/libxt_sctp.t
@@ -23,10 +23,7 @@ 
 -p sctp -m sctp --chunk-types all COOKIE_ACK;=;OK
 -p sctp -m sctp --chunk-types all ECN_ECNE;=;OK
 -p sctp -m sctp --chunk-types all ECN_CWR;=;OK
-# ERROR: iptables-save segfaults: iptables -A INPUT -p sctp -m sctp --chunk-types all ASCONF
-# -p sctp -m sctp --chunk-types all ASCONF;=;OK
-# ERROR: iptables-save segfaults: iptables -A INPUT -p sctp -m sctp --chunk-types all ASCONF_ACK
-# -p sctp -m sctp --chunk-types all ASCONF_ACK;=;OK
-# ERROR: iptables-save segfaults: iptables -A INPUT -p sctp -m sctp --chunk-types all FORWARD_TSN
-# -p sctp -m sctp --chunk-types all FORWARD_TSN;=;OK
+-p sctp -m sctp --chunk-types all ASCONF;=;OK
+-p sctp -m sctp --chunk-types all ASCONF_ACK;=;OK
+-p sctp -m sctp --chunk-types all FORWARD_TSN;=;OK
 -p sctp -m sctp --chunk-types all SHUTDOWN_COMPLETE;=;OK