[ Upstream commit 9a5a90d167b0e5fe3d47af16b68fd09ce64085cd ]
__netif_receive_skb_list_ptype() leaves skb->next poisoned before passing it to pt_prev->func handler, what may produce (in certain cases, e.g. DSA setup) crashes like:
[ 88.606777] CPU 0 Unable to handle kernel paging request at virtual address 0000000e, epc == 80687078, ra == 8052cc7c [ 88.618666] Oops[#1]: [ 88.621196] CPU: 0 PID: 0 Comm: swapper Not tainted 5.1.0-rc2-dlink-00206-g4192a172-dirty #1473 [ 88.630885] $ 0 : 00000000 10000400 00000002 864d7850 [ 88.636709] $ 4 : 87c0ddf0 864d7800 87c0ddf0 00000000 [ 88.642526] $ 8 : 00000000 49600000 00000001 00000001 [ 88.648342] $12 : 00000000 c288617b dadbee27 25d17c41 [ 88.654159] $16 : 87c0ddf0 85cff080 80790000 fffffffd [ 88.659975] $20 : 80797b20 ffffffff 00000001 864d7800 [ 88.665793] $24 : 00000000 8011e658 [ 88.671609] $28 : 80790000 87c0dbc0 87cabf00 8052cc7c [ 88.677427] Hi : 00000003 [ 88.680622] Lo : 7b5b4220 [ 88.683840] epc : 80687078 vlan_dev_hard_start_xmit+0x1c/0x1a0 [ 88.690532] ra : 8052cc7c dev_hard_start_xmit+0xac/0x188 [ 88.696734] Status: 10000404 IEp [ 88.700422] Cause : 50000008 (ExcCode 02) [ 88.704874] BadVA : 0000000e [ 88.708069] PrId : 0001a120 (MIPS interAptiv (multi)) [ 88.713005] Modules linked in: [ 88.716407] Process swapper (pid: 0, threadinfo=(ptrval), task=(ptrval), tls=00000000) [ 88.725219] Stack : 85f61c28 00000000 0000000e 80780000 87c0ddf0 85cff080 80790000 8052cc7c [ 88.734529] 87cabf00 00000000 00000001 85f5fb40 807b0000 864d7850 87cabf00 807d0000 [ 88.743839] 864d7800 8655f600 00000000 85cff080 87c1c000 0000006a 00000000 8052d96c [ 88.753149] 807a0000 8057adb8 87c0dcc8 87c0dc50 85cfff08 00000558 87cabf00 85f58c50 [ 88.762460] 00000002 85f58c00 864d7800 80543308 fffffff4 00000001 85f58c00 864d7800 [ 88.771770] ... [ 88.774483] Call Trace: [ 88.777199] [<80687078>] vlan_dev_hard_start_xmit+0x1c/0x1a0 [ 88.783504] [<8052cc7c>] dev_hard_start_xmit+0xac/0x188 [ 88.789326] [<8052d96c>] __dev_queue_xmit+0x6e8/0x7d4 [ 88.794955] [<805a8640>] ip_finish_output2+0x238/0x4d0 [ 88.800677] [<805ab6a0>] ip_output+0xc8/0x140 [ 88.805526] [<805a68f4>] ip_forward+0x364/0x560 [ 88.810567] [<805a4ff8>] ip_rcv+0x48/0xe4 [ 88.815030] [<80528d44>] __netif_receive_skb_one_core+0x44/0x58 [ 88.821635] [<8067f220>] dsa_switch_rcv+0x108/0x1ac [ 88.827067] [<80528f80>] __netif_receive_skb_list_core+0x228/0x26c [ 88.833951] [<8052ed84>] netif_receive_skb_list+0x1d4/0x394 [ 88.840160] [<80355a88>] lunar_rx_poll+0x38c/0x828 [ 88.845496] [<8052fa78>] net_rx_action+0x14c/0x3cc [ 88.850835] [<806ad300>] __do_softirq+0x178/0x338 [ 88.856077] [<8012a2d4>] irq_exit+0xbc/0x100 [ 88.860846] [<802f8b70>] plat_irq_dispatch+0xc0/0x144 [ 88.866477] [<80105974>] handle_int+0x14c/0x158 [ 88.871516] [<806acfb0>] r4k_wait+0x30/0x40 [ 88.876462] Code: afb10014 8c8200a0 00803025 <9443000c> 94a20468 00000000 10620042 00a08025 9605046a [ 88.887332] [ 88.888982] ---[ end trace eb863d007da11cf1 ]--- [ 88.894122] Kernel panic - not syncing: Fatal exception in interrupt [ 88.901202] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
Fix this by pulling skb off the sublist and zeroing skb->next pointer before calling ptype callback.
Fixes: 88eb1944e18c ("net: core: propagate SKB lists through packet_type lookup") Reviewed-by: Edward Cree ecree@solarflare.com Signed-off-by: Alexander Lobakin alobakin@dlink.ru Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/core/dev.c b/net/core/dev.c index 5c8c0a572ee9..d47554307a6d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4959,8 +4959,10 @@ static inline void __netif_receive_skb_list_ptype(struct list_head *head, if (pt_prev->list_func != NULL) pt_prev->list_func(head, pt_prev, orig_dev); else - list_for_each_entry_safe(skb, next, head, list) + list_for_each_entry_safe(skb, next, head, list) { + skb_list_del_init(skb); pt_prev->func(skb, skb->dev, pt_prev, orig_dev); + } }
static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)