kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 9653 Comm: syz-executor4 Not tainted 4.13.0-rc5-next-20170816+ #4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003a27a740 task.stack: ffff88003a1d0000 RIP: 0010:__read_once_size include/linux/compiler.h:276 [inline] RIP: 0010:compound_head include/linux/page-flags.h:146 [inline] RIP: 0010:put_page include/linux/mm.h:811 [inline] RIP: 0010:__skb_frag_unref include/linux/skbuff.h:2743 [inline] RIP: 0010:skb_release_data+0x26c/0x790 net/core/skbuff.c:568 RSP: 0018:ffff88003a1d6e08 EFLAGS: 00010207 RAX: 0533c435781dcaf3 RBX: dffffc0000000000 RCX: ffffc90003d1e000 RDX: 000000000000019f RSI: ffffffff83e00427 RDI: 299e21abc0ee579f RBP: ffff88003a1d6f28 R08: 0000000000000000 R09: 1ffff1000743addc R10: ffff88003a1d6ea8 R11: ffff88002a183778 R12: ffff88005603b070 R13: ffffed000743add8 R14: 1ffff1000743add0 R15: 299e21abc0ee577f FS: 00007f3469501700(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001ddbc23000 CR3: 000000006cedb000 CR4: 00000000000026f0 DR0: 0000000020000000 DR1: 0000000020001000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: skb_release_all+0x4a/0x60 net/core/skbuff.c:631 __kfree_skb net/core/skbuff.c:645 [inline] kfree_skb+0x15d/0x4c0 net/core/skbuff.c:663 llc_rcv+0x5b1/0xde0 net/llc/llc_input.c:214 __netif_receive_skb_core+0x19af/0x33d0 net/core/dev.c:4418 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4456 netif_receive_skb_internal+0x10b/0x5e0 net/core/dev.c:4527 netif_receive_skb+0xae/0x390 net/core/dev.c:4551 tun_rx_batched.isra.43+0x5e7/0x860 drivers/net/tun.c:1221 tun_get_user+0x11dd/0x2150 drivers/net/tun.c:1542 tun_chr_write_iter+0xd8/0x190 drivers/net/tun.c:1568 call_write_iter include/linux/fs.h:1742 [inline] new_sync_write fs/read_write.c:457 [inline] __vfs_write+0x684/0x970 fs/read_write.c:470 vfs_write+0x189/0x510 fs/read_write.c:518 SYSC_write fs/read_write.c:565 [inline] SyS_write+0xef/0x220 fs/read_write.c:557 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x40bab1 RSP: 002b:00007f3469500c00 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000000002f5 RCX: 000000000040bab1 RDX: 00000000000002f5 RSI: 00000000200c0d0b RDI: 0000000000000015 RBP: 0000000000a5f870 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f34695019c0 R15: 00007f3469501700 Code: c6 e8 c9 68 8d fd 4c 89 e0 48 c1 e8 03 80 3c 18 00 0f 85 93 04 00 00 4d 8b 3c 24 41 c6 45 00 00 49 8d 7f 20 48 89 f8 48 c1 e8 03 <80> 3c 18 00 0f 85 6b 04 00 00 41 80 7d 00 00 49 8b 47 20 0f 85 RIP: __read_once_size include/linux/compiler.h:276 [inline] RSP: ffff88003a1d6e08 RIP: compound_head include/linux/page-flags.h:146 [inline] RSP: ffff88003a1d6e08 RIP: put_page include/linux/mm.h:811 [inline] RSP: ffff88003a1d6e08 RIP: __skb_frag_unref include/linux/skbuff.h:2743 [inline] RSP: ffff88003a1d6e08 RIP: skb_release_data+0x26c/0x790 net/core/skbuff.c:568 RSP: ffff88003a1d6e08 ---[ end trace acc8e16108ef5d0c ]---