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 <subas...@codeaurora.org> --- drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c index 6908b26..1f98d65 100644 --- 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(struct sk_buff *skb, } 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; } -- 1.9.1