================================================================== BUG: KASAN: use-after-free in __xfrm6_tunnel_spi_lookup+0x3a9/0x3b0 net/ipv6/xfrm6_tunnel.c:79 Read of size 8 at addr ffff88809c945228 by task syz-executor.1/11885 CPU: 0 PID: 11885 Comm: syz-executor.1 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 tunnel46_rcv+0xef/0x2b0 net/ipv6/tunnel6.c:193 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:00007f2417db9c60 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000078bf00 RCX: 0000000000415c91 RDX: 0000000000000062 RSI: 0000000020000000 RDI: 00000000000000f0 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 00007f2417dba9d0 R11: 0000000000000293 R12: 000000000078bf0c R13: 00007ffee355664f R14: 00007f2417dba9c0 R15: 000000000078bf0c Allocated by task 11407: 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 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x1a8/0x320 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] kzalloc include/linux/slab.h:666 [inline] tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline] tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x186/0x620 security/tomoyo/realpath.c:288 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x272/0x380 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:313 [inline] tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:308 security_file_open+0x52/0x470 security/security.c:1583 do_dentry_open+0x358/0x11b0 fs/open.c:809 do_open fs/namei.c:3249 [inline] path_openat+0x1b97/0x2720 fs/namei.c:3366 do_filp_open+0x17e/0x3c0 fs/namei.c:3393 do_sys_openat2+0x16d/0x3e0 fs/open.c:1173 do_sys_open fs/open.c:1189 [inline] ksys_open include/linux/syscalls.h:1398 [inline] __do_sys_open fs/open.c:1195 [inline] __se_sys_open fs/open.c:1193 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1193 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 ffff88809c945200 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 40 bytes inside of 64-byte region [ffff88809c945200, ffff88809c945240) The buggy address belongs to the page: page:00000000719fd098 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9c945 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002557c08 ffffea00028cd448 ffff8880aa000200 raw: 0000000000000000 ffff88809c945000 0000000100000020 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809c945100: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff88809c945180: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff88809c945200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff88809c945280: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff88809c945300: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================