From: Xin Long lucien.xin@gmail.com
[ Upstream commit 2f201ae14ae0f91dbf1cffea7bb1e29e81d4d108 ]
A crash was reported by Zhen Chen:
list_del corruption, ffffa035ddf01c18->next is NULL WARNING: CPU: 1 PID: 250682 at lib/list_debug.c:49 __list_del_entry_valid+0x59/0xe0 RIP: 0010:__list_del_entry_valid+0x59/0xe0 Call Trace: sctp_sched_dequeue_common+0x17/0x70 [sctp] sctp_sched_fcfs_dequeue+0x37/0x50 [sctp] sctp_outq_flush_data+0x85/0x360 [sctp] sctp_outq_uncork+0x77/0xa0 [sctp] sctp_cmd_interpreter.constprop.0+0x164/0x1450 [sctp] sctp_side_effects+0x37/0xe0 [sctp] sctp_do_sm+0xd0/0x230 [sctp] sctp_primitive_SEND+0x2f/0x40 [sctp] sctp_sendmsg_to_asoc+0x3fa/0x5c0 [sctp] sctp_sendmsg+0x3d5/0x440 [sctp] sock_sendmsg+0x5b/0x70
and in sctp_sched_fcfs_dequeue() it dequeued a chunk from stream out_curr outq while this outq was empty.
Normally stream->out_curr must be set to NULL once all frag chunks of current msg are dequeued, as we can see in sctp_sched_dequeue_done(). However, in sctp_prsctp_prune_unsent() as it is not a proper dequeue, sctp_sched_dequeue_done() is not called to do this.
This patch is to fix it by simply setting out_curr to NULL when the last frag chunk of current msg is dequeued from out_curr stream in sctp_prsctp_prune_unsent().
Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") Reported-by: Zhen Chen chenzhen126@huawei.com Tested-by: Caowangbao caowangbao@huawei.com Signed-off-by: Xin Long lucien.xin@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/sctp/outqueue.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index 35d5532320f9..83a89dcf75ed 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -403,6 +403,11 @@ static int sctp_prsctp_prune_unsent(struct sctp_association *asoc, sout = SCTP_SO(&asoc->stream, chk->sinfo.sinfo_stream); sout->ext->abandoned_unsent[SCTP_PR_INDEX(PRIO)]++;
+ /* clear out_curr if all frag chunks are pruned */ + if (asoc->stream.out_curr == sout && + list_is_last(&chk->frag_list, &chk->msg->chunks)) + asoc->stream.out_curr = NULL; + msg_len -= chk->skb->truesize + sizeof(struct sctp_chunk); sctp_chunk_free(chk); if (msg_len <= 0)