================================================================== BUG: KASAN: use-after-free in __xfrm6_tunnel_spi_lookup+0x3a9/0x3b0 net/ipv6/xfrm6_tunnel.c:79 Read of size 8 at addr ffff88809cb722a0 by task syz-executor.3/14903 CPU: 1 PID: 14903 Comm: syz-executor.3 Not tainted 5.8.0-rc5-next-20200715-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+0x59d/0x6b0 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: 0033:0x416661 Code: Bad RIP value. RSP: 002b:00007fd33e946c60 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050b3c0 RCX: 0000000000416661 RDX: 0000000000001162 RSI: 0000000020000180 RDI: 00000000000000f0 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 00007fd33e9479d0 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c4a R14: 00000000004ce8f4 R15: 00007fd33e9476d4 Allocated by task 7187: 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_node include/linux/slab.h:577 [inline] kvmalloc_node+0x61/0xf0 mm/util.c:574 kvmalloc include/linux/mm.h:760 [inline] kvmalloc_array include/linux/mm.h:778 [inline] alloc_fdtable+0xcd/0x280 fs/file.c:118 dup_fd+0x726/0xc90 fs/file.c:323 copy_files kernel/fork.c:1459 [inline] copy_process+0x1dd0/0x6b70 kernel/fork.c:2064 _do_fork+0xe8/0xb10 kernel/fork.c:2434 __do_sys_clone+0xc8/0x110 kernel/fork.c:2551 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 14812: 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 kvfree+0x42/0x50 mm/util.c:603 __free_fdtable fs/file.c:34 [inline] put_files_struct fs/file.c:433 [inline] put_files_struct+0x267/0x350 fs/file.c:426 exit_files+0x7e/0xa0 fs/file.c:458 do_exit+0xb43/0x29f0 kernel/exit.c:801 do_group_exit+0x125/0x310 kernel/exit.c:903 get_signal+0x40b/0x1ee0 kernel/signal.c:2743 do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810 exit_to_usermode_loop arch/x86/entry/common.c:235 [inline] __prepare_exit_to_usermode+0x14d/0x1f0 arch/x86/entry/common.c:269 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:393 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88809cb72000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 672 bytes inside of 2048-byte region [ffff88809cb72000, ffff88809cb72800) The buggy address belongs to the page: page:00000000666a4220 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9cb72 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00013295c8 ffffea0002860b48 ffff8880aa000800 raw: 0000000000000000 ffff88809cb72000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809cb72180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809cb72200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88809cb72280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809cb72300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809cb72380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================