Acked. ///jon
> -----Original Message----- > From: Jia-Ju Bai [mailto:baijiaju1...@163.com] > Sent: Saturday, June 10, 2017 05:04 > To: Jon Maloy <jon.ma...@ericsson.com>; Ying Xue > <ying....@windriver.com>; da...@davemloft.net > Cc: netdev@vger.kernel.org; tipc-discuss...@lists.sourceforge.net; linux- > ker...@vger.kernel.org; Jia-Ju Bai <baijiaju1...@163.com> > Subject: [PATCH] net: tipc: Fix a sleep-in-atomic bug in tipc_msg_reverse > > The kernel may sleep under a rcu read lock in tipc_msg_reverse, and the > function call path is: > tipc_l2_rcv_msg (acquire the lock by rcu_read_lock) > tipc_rcv > tipc_sk_rcv > tipc_msg_reverse > pskb_expand_head(GFP_KERNEL) --> may sleep tipc_node_broadcast > tipc_node_xmit_skb > tipc_node_xmit > tipc_sk_rcv > tipc_msg_reverse > pskb_expand_head(GFP_KERNEL) --> may sleep > > To fix it, "GFP_KERNEL" is replaced with "GFP_ATOMIC". > > Signed-off-by: Jia-Ju Bai <baijiaju1...@163.com> > --- > net/tipc/msg.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/tipc/msg.c b/net/tipc/msg.c index 312ef7d..ab30876 100644 > --- a/net/tipc/msg.c > +++ b/net/tipc/msg.c > @@ -508,7 +508,7 @@ bool tipc_msg_reverse(u32 own_node, struct > sk_buff **skb, int err) > } > > if (skb_cloned(_skb) && > - pskb_expand_head(_skb, BUF_HEADROOM, BUF_TAILROOM, > GFP_KERNEL)) > + pskb_expand_head(_skb, BUF_HEADROOM, BUF_TAILROOM, > GFP_ATOMIC)) > goto exit; > > /* Now reverse the concerned fields */ > -- > 1.7.9.5 >
