4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Subash Abhinov Kasiviswanathan <[email protected]>

[ Upstream commit 6392ff3c8e4c23d0a09b0ae9f94feb3effed490b ]

The incoming skb needs to be reallocated in case the headroom
is not sufficient to add the MAP header. This allocation needs to
be atomic otherwise it results in the following splat

[32805.801456] BUG: sleeping function called from invalid context
[32805.841141] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[32805.904773] task: ffffffd7c5f62280 task.stack: ffffff80464a8000
[32805.910851] pc : ___might_sleep+0x180/0x188
[32805.915143] lr : ___might_sleep+0x180/0x188
[32806.131520] Call trace:
[32806.134041]  ___might_sleep+0x180/0x188
[32806.137980]  __might_sleep+0x50/0x84
[32806.141653]  __kmalloc_track_caller+0x80/0x3bc
[32806.146215]  __kmalloc_reserve+0x3c/0x88
[32806.150241]  pskb_expand_head+0x74/0x288
[32806.154269]  rmnet_egress_handler+0xb0/0x1d8
[32806.162239]  rmnet_vnd_start_xmit+0xc8/0x13c
[32806.166627]  dev_hard_start_xmit+0x148/0x280
[32806.181181]  sch_direct_xmit+0xa4/0x198
[32806.185125]  __qdisc_run+0x1f8/0x310
[32806.188803]  net_tx_action+0x23c/0x26c
[32806.192655]  __do_softirq+0x220/0x408
[32806.196420]  do_softirq+0x4c/0x70

Fixes: ceed73a2cf4a ("drivers: net: ethernet: qualcomm: rmnet: Initial 
implementation")
Signed-off-by: Subash Abhinov Kasiviswanathan <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
@@ -147,7 +147,7 @@ static int rmnet_map_egress_handler(stru
        }
 
        if (skb_headroom(skb) < required_headroom) {
-               if (pskb_expand_head(skb, required_headroom, 0, GFP_KERNEL))
+               if (pskb_expand_head(skb, required_headroom, 0, GFP_ATOMIC))
                        return -ENOMEM;
        }
 


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