device veth1_macvtap left promiscuous mode
device veth0_macvtap left promiscuous mode
device veth1_vlan left promiscuous mode
device veth0_vlan left promiscuous mode
==================================================================
BUG: KASAN: use-after-free in tcp_retransmit_timer+0x305e/0x3470 net/ipv4/tcp_timer.c:485
Read of size 8 at addr ffff88804ed0c3b8 by task swapper/1/0

CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.187-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 tcp_retransmit_timer+0x305e/0x3470 net/ipv4/tcp_timer.c:485
 tcp_write_timer_handler+0x5e6/0xa60 net/ipv4/tcp_timer.c:598
 tcp_write_timer+0x103/0x1b0 net/ipv4/tcp_timer.c:618
 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338
 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375
 __run_timers kernel/time/timer.c:1696 [inline]
 run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709
 __do_softirq+0x265/0x980 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x215/0x260 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:535 [inline]
 smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: 48 89 df e8 64 4b 80 f9 e9 2e ff ff ff 48 89 df e8 57 4b 80 f9 eb 82 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 24 b1 4f 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 14 b1 4f 00 f4 c3 90 90 41 56 41 55
RSP: 0018:ffff8880b5aafd40 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff13e304c RBX: dffffc0000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff8880b5aa0c44
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89f18250
R13: 1ffff11016b55fb2 R14: 0000000000000000 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
 default_idle+0x49/0x310 arch/x86/kernel/process.c:557
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x2ec/0x4b0 kernel/sched/idle.c:263
 cpu_startup_entry+0xc5/0xe0 kernel/sched/idle.c:369
 start_secondary+0x435/0x5c0 arch/x86/kernel/smpboot.c:271
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

Allocated by task 8130:
 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
 kmem_cache_zalloc include/linux/slab.h:699 [inline]
 net_alloc net/core/net_namespace.c:385 [inline]
 copy_net_ns+0x106/0x340 net/core/net_namespace.c:425
 create_new_namespaces+0x3f6/0x7b0 kernel/nsproxy.c:107
 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:206
 ksys_unshare+0x36c/0x9a0 kernel/fork.c:2541
 __do_sys_unshare kernel/fork.c:2609 [inline]
 __se_sys_unshare kernel/fork.c:2607 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:2607
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3552:
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x7f/0x260 mm/slab.c:3765
 net_free net/core/net_namespace.c:401 [inline]
 net_drop_ns+0x73/0x90 net/core/net_namespace.c:408
 cleanup_net+0x64c/0x8b0 net/core/net_namespace.c:571
 process_one_work+0x864/0x1570 kernel/workqueue.c:2152
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2295
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

The buggy address belongs to the object at ffff88804ed0c180
 which belongs to the cache net_namespace of size 8704
The buggy address is located 568 bytes inside of
 8704-byte region [ffff88804ed0c180, ffff88804ed0e380)
The buggy address belongs to the page:
page:ffffea00013b4300 count:1 mapcount:0 mapping:ffff88823b843e00 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea00013e5908 ffffea000135a108 ffff88823b843e00
raw: 0000000000000000 ffff88804ed0c180 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804ed0c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804ed0c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88804ed0c380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff88804ed0c400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804ed0c480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================