From 343eba69c6968190d8654b857aea952fed9a6749 Mon Sep 17 00:00:00 2001 From: Jia-Ju Bai Date: Sat, 10 Jun 2017 17:03:35 +0800 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 Signed-off-by: David S. Miller --- 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 312ef7de57d7..ab3087687a32 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 */ -- 2.20.1