From: Eric Dumazet edumazet@google.com
[ Upstream commit 9eed321cde22fc1afd76eac563ce19d899e0d6b2 ]
It probbaly makes no sense to support arbitrary network devices for lapbether.
syzbot reported:
skbuff: skb_under_panic: text:ffff80008934c100 len:44 put:40 head:ffff0000d18dd200 data:ffff0000d18dd1ea tail:0x16 end:0x140 dev:bond1 kernel BUG at net/core/skbuff.c:200 ! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 5643 Comm: dhcpcd Not tainted 6.4.0-rc5-syzkaller-g4641cff8e810 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : skb_panic net/core/skbuff.c:196 [inline] pc : skb_under_panic+0x13c/0x140 net/core/skbuff.c:210 lr : skb_panic net/core/skbuff.c:196 [inline] lr : skb_under_panic+0x13c/0x140 net/core/skbuff.c:210 sp : ffff8000973b7260 x29: ffff8000973b7270 x28: ffff8000973b7360 x27: dfff800000000000 x26: ffff0000d85d8150 x25: 0000000000000016 x24: ffff0000d18dd1ea x23: ffff0000d18dd200 x22: 000000000000002c x21: 0000000000000140 x20: 0000000000000028 x19: ffff80008934c100 x18: ffff8000973b68a0 x17: 0000000000000000 x16: ffff80008a43bfbc x15: 0000000000000202 x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000001 x11: 0000000000000201 x10: 0000000000000000 x9 : f22f7eb937cced00 x8 : f22f7eb937cced00 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff8000973b6b78 x4 : ffff80008df9ee80 x3 : ffff8000805974f4 x2 : 0000000000000001 x1 : 0000000100000201 x0 : 0000000000000086 Call trace: skb_panic net/core/skbuff.c:196 [inline] skb_under_panic+0x13c/0x140 net/core/skbuff.c:210 skb_push+0xf0/0x108 net/core/skbuff.c:2409 ip6gre_header+0xbc/0x738 net/ipv6/ip6_gre.c:1383 dev_hard_header include/linux/netdevice.h:3137 [inline] lapbeth_data_transmit+0x1c4/0x298 drivers/net/wan/lapbether.c:257 lapb_data_transmit+0x8c/0xb0 net/lapb/lapb_iface.c:447 lapb_transmit_buffer+0x178/0x204 net/lapb/lapb_out.c:149 lapb_send_control+0x220/0x320 net/lapb/lapb_subr.c:251 lapb_establish_data_link+0x94/0xec lapb_device_event+0x348/0x4e0 notifier_call_chain+0x1a4/0x510 kernel/notifier.c:93 raw_notifier_call_chain+0x3c/0x50 kernel/notifier.c:461 __dev_notify_flags+0x2bc/0x544 dev_change_flags+0xd0/0x15c net/core/dev.c:8643 devinet_ioctl+0x858/0x17e4 net/ipv4/devinet.c:1150 inet_ioctl+0x2ac/0x4d8 net/ipv4/af_inet.c:979 sock_do_ioctl+0x134/0x2dc net/socket.c:1201 sock_ioctl+0x4ec/0x858 net/socket.c:1318 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191 el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Code: aa1803e6 aa1903e7 a90023f5 947730f5 (d4210000)
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Eric Dumazet edumazet@google.com Cc: Martin Schiller ms@dev.tdt.de Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wan/lapbether.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c index d62a904d2e422..56326f38fe8a3 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -384,6 +384,9 @@ static int lapbeth_new_device(struct net_device *dev)
ASSERT_RTNL();
+ if (dev->type != ARPHRD_ETHER) + return -EINVAL; + ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN, lapbeth_setup); if (!ndev)