The kernel may sleep under a rcu read lock in cfpkt_create_pfx, and the
function call path is:
cfcnfg_linkup_rsp (acquire the lock by rcu_read_lock)
cfctrl_linkdown_req
cfpkt_create
cfpkt_create_pfx
alloc_skb(GFP_KERNEL) --> may sleep
cfserl_receive (acquire the lock by rcu_read_lock)
cfpkt_split
cfpkt_create_pfx
alloc_skb(GFP_KERNEL) --> may sleep
There is "in_interrupt" in cfpkt_create_pfx to decide use "GFP_KERNEL" or
"GFP_ATOMIC". In this situation, "GFP_KERNEL" is used because the function
is called under a rcu read lock, instead in interrupt.
To fix it, only "GFP_ATOMIC" is used in cfpkt_create_pfx.
Signed-off-by: Jia-Ju Bai
---
net/caif/cfpkt_skbuff.c |6 +-
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/net/caif/cfpkt_skbuff.c b/net/caif/cfpkt_skbuff.c
index 59ce1fc..71b6ab2 100644
--- a/net/caif/cfpkt_skbuff.c
+++ b/net/caif/cfpkt_skbuff.c
@@ -81,11 +81,7 @@ static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx)
{
struct sk_buff *skb;
- if (likely(in_interrupt()))
- skb = alloc_skb(len + pfx, GFP_ATOMIC);
- else
- skb = alloc_skb(len + pfx, GFP_KERNEL);
-
+ skb = alloc_skb(len + pfx, GFP_ATOMIC);
if (unlikely(skb == NULL))
return NULL;
--
1.7.9.5
