================================================================== BUG: KASAN: slab-out-of-bounds in __xfrm6_tunnel_spi_lookup+0x3a9/0x3b0 net/ipv6/xfrm6_tunnel.c:79 Read of size 8 at addr ffff8880945a96a0 by task syz-executor.4/26637 CPU: 1 PID: 26637 Comm: syz-executor.4 Not tainted 5.8.0-rc5-next-20200716-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 __xfrm6_tunnel_spi_lookup+0x3a9/0x3b0 net/ipv6/xfrm6_tunnel.c:79 xfrm6_tunnel_spi_lookup+0x8a/0x1d0 net/ipv6/xfrm6_tunnel.c:95 xfrmi6_rcv_tunnel+0xb9/0x100 net/xfrm/xfrm_interface.c:824 tunnel6_rcv+0xef/0x2b0 net/ipv6/tunnel6.c:148 ip6_protocol_deliver_rcu+0x2e8/0x1670 net/ipv6/ip6_input.c:433 ip6_input_finish+0x7f/0x160 net/ipv6/ip6_input.c:474 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:483 dst_input include/net/dst.h:449 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x28e/0x3c0 net/ipv6/ip6_input.c:307 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5287 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5401 netif_receive_skb_internal net/core/dev.c:5503 [inline] netif_receive_skb+0x159/0x990 net/core/dev.c:5562 tun_rx_batched.isra.0+0x460/0x720 drivers/net/tun.c:1518 tun_get_user+0x23b2/0x35b0 drivers/net/tun.c:1972 tun_chr_write_iter+0xba/0x151 drivers/net/tun.c:2001 call_write_iter include/linux/fs.h:1879 [inline] new_sync_write+0x422/0x650 fs/read_write.c:515 vfs_write+0x5c6/0x6f0 fs/read_write.c:595 ksys_write+0x12d/0x250 fs/read_write.c:648 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x415c91 Code: Bad RIP value. RSP: 002b:00007f3241596c60 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000078bf00 RCX: 0000000000415c91 RDX: 000000000000010e RSI: 00000000200001c0 RDI: 00000000000000f0 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 00007f32415979d0 R11: 0000000000000293 R12: 000000000078bf0c R13: 00007fffaac967ff R14: 00007f32415979c0 R15: 000000000078bf0c Allocated by task 26589: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 __kmalloc_reserve net/core/skbuff.c:142 [inline] pskb_expand_head+0x15a/0x1040 net/core/skbuff.c:1627 skb_ensure_writable net/core/skbuff.c:5457 [inline] skb_ensure_writable+0x2c7/0x450 net/core/skbuff.c:5449 __bpf_try_make_writable net/core/filter.c:1627 [inline] bpf_try_make_writable net/core/filter.c:1633 [inline] bpf_try_make_head_writable net/core/filter.c:1641 [inline] ____bpf_clone_redirect net/core/filter.c:2162 [inline] bpf_clone_redirect+0x125/0x420 net/core/filter.c:2140 0xffffffffa0052a17 bpf_dispatcher_nop_func include/linux/bpf.h:567 [inline] bpf_test_run+0x3bb/0xc70 net/bpf/test_run.c:49 bpf_prog_test_run_skb+0x98b/0x14f0 net/bpf/test_run.c:459 bpf_prog_test_run kernel/bpf/syscall.c:2986 [inline] __do_sys_bpf+0x2117/0x4b10 kernel/bpf/syscall.c:4138 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 26589: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kfree+0x103/0x2c0 mm/slab.c:3756 skb_free_head net/core/skbuff.c:590 [inline] pskb_expand_head+0xb0c/0x1040 net/core/skbuff.c:1660 __skb_cow include/linux/skbuff.h:3146 [inline] skb_cow_head include/linux/skbuff.h:3180 [inline] ipgre_xmit+0x345/0x9f0 net/ipv4/ip_gre.c:629 __netdev_start_xmit include/linux/netdevice.h:4621 [inline] netdev_start_xmit include/linux/netdevice.h:4635 [inline] xmit_one net/core/dev.c:3562 [inline] dev_hard_start_xmit+0x193/0x950 net/core/dev.c:3578 __dev_queue_xmit+0x2096/0x2d60 net/core/dev.c:4137 __bpf_tx_skb net/core/filter.c:2089 [inline] __bpf_redirect_no_mac net/core/filter.c:2114 [inline] __bpf_redirect+0x52e/0xc60 net/core/filter.c:2137 ____bpf_clone_redirect net/core/filter.c:2168 [inline] bpf_clone_redirect+0x2ae/0x420 net/core/filter.c:2140 0xffffffffa0052a17 bpf_dispatcher_nop_func include/linux/bpf.h:567 [inline] bpf_test_run+0x3bb/0xc70 net/bpf/test_run.c:49 bpf_prog_test_run_skb+0x98b/0x14f0 net/bpf/test_run.c:459 bpf_prog_test_run kernel/bpf/syscall.c:2986 [inline] __do_sys_bpf+0x2117/0x4b10 kernel/bpf/syscall.c:4138 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880945a9400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 160 bytes to the right of 512-byte region [ffff8880945a9400, ffff8880945a9600) The buggy address belongs to the page: page:000000004d0eac1e refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x945a9 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00029d9e48 ffffea00024ffb08 ffff8880aa000600 raw: 0000000000000000 ffff8880945a9000 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880945a9580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880945a9600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880945a9680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880945a9700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880945a9780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================