[PATCH 4.4 55/70] sctp: use right member as the param of list_for_each_entry

From: Greg Kroah-Hartman
Date: Fri May 01 2020 - 10:00:46 EST


From: Xin Long <lucien.xin@xxxxxxxxx>

commit a8dd397903a6e57157f6265911f7d35681364427 upstream.

Commit d04adf1b3551 ("sctp: reset owner sk for data chunks on out queues
when migrating a sock") made a mistake that using 'list' as the param of
list_for_each_entry to traverse the retransmit, sacked and abandoned
queues, while chunks are using 'transmitted_list' to link into these
queues.

It could cause NULL dereference panic if there are chunks in any of these
queues when peeling off one asoc.

So use the chunk member 'transmitted_list' instead in this patch.

Fixes: d04adf1b3551 ("sctp: reset owner sk for data chunks on out queues when migrating a sock")
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/sctp/socket.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -185,13 +185,13 @@ static void sctp_for_each_tx_datachunk(s
list_for_each_entry(chunk, &t->transmitted, transmitted_list)
cb(chunk);

- list_for_each_entry(chunk, &q->retransmit, list)
+ list_for_each_entry(chunk, &q->retransmit, transmitted_list)
cb(chunk);

- list_for_each_entry(chunk, &q->sacked, list)
+ list_for_each_entry(chunk, &q->sacked, transmitted_list)
cb(chunk);

- list_for_each_entry(chunk, &q->abandoned, list)
+ list_for_each_entry(chunk, &q->abandoned, transmitted_list)
cb(chunk);

list_for_each_entry(chunk, &q->out_chunk_list, list)