From: Eric Dumazet edumazet@google.com
[ Upstream commit f32f19339596b214c208c0dba716f4b6cc4f6958 ]
syzbot managed to crash a host by creating a bond with a GRE device.
For non Ethernet device, bonding calls bond_setup_by_slave() instead of ether_setup(), and unfortunately dev->needed_headroom was not copied from the new added member.
[ 171.243095] skbuff: skb_under_panic: text:ffffffffa184b9ea len:116 put:20 head:ffff883f84012dc0 data:ffff883f84012dbc tail:0x70 end:0xd00 dev:bond0 [ 171.243111] ------------[ cut here ]------------ [ 171.243112] kernel BUG at net/core/skbuff.c:112! [ 171.243117] invalid opcode: 0000 [#1] SMP KASAN PTI [ 171.243469] gsmi: Log Shutdown Reason 0x03 [ 171.243505] Call Trace: [ 171.243506] <IRQ> [ 171.243512] [<ffffffffa171be59>] skb_push+0x49/0x50 [ 171.243516] [<ffffffffa184b9ea>] ipgre_header+0x2a/0xf0 [ 171.243520] [<ffffffffa17452d7>] neigh_connected_output+0xb7/0x100 [ 171.243524] [<ffffffffa186f1d3>] ip6_finish_output2+0x383/0x490 [ 171.243528] [<ffffffffa186ede2>] __ip6_finish_output+0xa2/0x110 [ 171.243531] [<ffffffffa186acbc>] ip6_finish_output+0x2c/0xa0 [ 171.243534] [<ffffffffa186abe9>] ip6_output+0x69/0x110 [ 171.243537] [<ffffffffa186ac90>] ? ip6_output+0x110/0x110 [ 171.243541] [<ffffffffa189d952>] mld_sendpack+0x1b2/0x2d0 [ 171.243544] [<ffffffffa189d290>] ? mld_send_report+0xf0/0xf0 [ 171.243548] [<ffffffffa189c797>] mld_ifc_timer_expire+0x2d7/0x3b0 [ 171.243551] [<ffffffffa189c4c0>] ? mld_gq_timer_expire+0x50/0x50 [ 171.243556] [<ffffffffa0fea270>] call_timer_fn+0x30/0x130 [ 171.243559] [<ffffffffa0fea17c>] expire_timers+0x4c/0x110 [ 171.243563] [<ffffffffa0fea0e3>] __run_timers+0x213/0x260 [ 171.243566] [<ffffffffa0fecb7d>] ? ktime_get+0x3d/0xa0 [ 171.243570] [<ffffffffa0ff9c4e>] ? clockevents_program_event+0x7e/0xe0 [ 171.243574] [<ffffffffa0f7e5d5>] ? sched_clock_cpu+0x15/0x190 [ 171.243577] [<ffffffffa0fe973d>] run_timer_softirq+0x1d/0x40 [ 171.243581] [<ffffffffa1c00152>] __do_softirq+0x152/0x2f0 [ 171.243585] [<ffffffffa0f44e1f>] irq_exit+0x9f/0xb0 [ 171.243588] [<ffffffffa1a02e1d>] smp_apic_timer_interrupt+0xfd/0x1a0 [ 171.243591] [<ffffffffa1a01ea6>] apic_timer_interrupt+0x86/0x90
Fixes: f5184d267c1a ("net: Allow netdevices to specify needed head/tailroom") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/bonding/bond_main.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index d32e32e79174..a59333b87eaf 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1123,6 +1123,7 @@ static void bond_setup_by_slave(struct net_device *bond_dev,
bond_dev->type = slave_dev->type; bond_dev->hard_header_len = slave_dev->hard_header_len; + bond_dev->needed_headroom = slave_dev->needed_headroom; bond_dev->addr_len = slave_dev->addr_len;
memcpy(bond_dev->broadcast, slave_dev->broadcast,