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authorJon Paul Maloy <jon.maloy@ericsson.com>2014-07-05 13:44:13 -0400
committerDavid S. Miller <davem@davemloft.net>2014-07-08 15:55:09 -0700
commit29322d0db98e5a84f5cc6a55655bee3dc4ffb5ab (patch)
treed25dfe81b741b6a8757ff1eea5143b1c3a801e7c /net
parentb6e195fd4f663a7a97183feddb4ec27f0a5a00ec (diff)
downloadlinux-29322d0db98e5a84f5cc6a55655bee3dc4ffb5ab.tar.bz2
tipc: fix bug in multicast/broadcast message reassembly
Since commit 37e22164a8a3c39bdad45aa463b1e69a1fdf4110 ("tipc: rename and move message reassembly function") reassembly of long broadcast messages has been broken. This is because we test for a non-NULL return value of the *buf parameter as criteria for succesful reassembly. However, this parameter is left defined even after reception of the first fragment, when reassebly is still incomplete. This leads to a kernel crash as soon as a the first fragment of a long broadcast message is received. We fix this with this commit, by implementing a stricter behavior of the function and its return values. This commit should be applied to both net and net-next. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/tipc/msg.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index 8be6e94a1ca9..0a37a472c29f 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -101,9 +101,11 @@ int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
}
/* tipc_buf_append(): Append a buffer to the fragment list of another buffer
- * Let first buffer become head buffer
- * Returns 1 and sets *buf to headbuf if chain is complete, otherwise 0
- * Leaves headbuf pointer at NULL if failure
+ * @*headbuf: in: NULL for first frag, otherwise value returned from prev call
+ * out: set when successful non-complete reassembly, otherwise NULL
+ * @*buf: in: the buffer to append. Always defined
+ * out: head buf after sucessful complete reassembly, otherwise NULL
+ * Returns 1 when reassembly complete, otherwise 0
*/
int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
{
@@ -122,6 +124,7 @@ int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
goto out_free;
head = *headbuf = frag;
skb_frag_list_init(head);
+ *buf = NULL;
return 0;
}
if (!head)
@@ -150,5 +153,7 @@ int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
out_free:
pr_warn_ratelimited("Unable to build fragment list\n");
kfree_skb(*buf);
+ kfree_skb(*headbuf);
+ *buf = *headbuf = NULL;
return 0;
}