================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2b80/0x2f20 net/ipv4/tcp_timer.c:480 Read of size 8 at addr ffff88806bbe03b8 by task udevd/18358 CPU: 1 PID: 18358 Comm: udevd Not tainted 5.2.0-rc1+ #7 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 tcp_retransmit_timer+0x2b80/0x2f20 net/ipv4/tcp_timer.c:480 tcp_write_timer_handler+0x591/0x8a0 net/ipv4/tcp_timer.c:591 tcp_write_timer+0x10e/0x1d0 net/ipv4/tcp_timer.c:611 call_timer_fn+0x193/0x720 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x66f/0x1740 kernel/time/timer.c:1698 __do_softirq+0x25c/0x94c kernel/softirq.c:293 invoke_softirq kernel/softirq.c:374 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:414 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13b/0x550 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 RIP: 0010:__sanitizer_cov_trace_pc+0x4b/0x50 kernel/kcov.c:112 Code: 90 e0 12 00 00 83 fa 02 75 20 48 8b 88 e8 12 00 00 8b 80 e4 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 <5d> c3 0f 1f 00 65 4c 8b 04 25 c0 fd 01 00 65 8b 05 b8 58 91 7e a9 RSP: 0000:ffff88806934fcd0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff88806b500000 RBX: ffff888095aea318 RCX: ffffffff819b0ea6 RDX: 0000000000000000 RSI: ffffffff819b0ebb RDI: 0000000000000007 RBP: ffff88806934fcd0 R08: ffff88806b500000 R09: ffff88806934fd68 R10: ffffed1015d26bdf R11: ffff8880ae935efb R12: 00007f4c969b3000 R13: ffff88806934fe18 R14: 0000000000000000 R15: 000000000000000f do_fault_around mm/memory.c:3498 [inline] do_read_fault mm/memory.c:3532 [inline] do_fault mm/memory.c:3666 [inline] handle_pte_fault mm/memory.c:3897 [inline] __handle_mm_fault+0x317b/0x3eb0 mm/memory.c:4021 handle_mm_fault+0x3b7/0xa90 mm/memory.c:4058 do_user_addr_fault arch/x86/mm/fault.c:1457 [inline] __do_page_fault+0x5ef/0xda0 arch/x86/mm/fault.c:1523 do_page_fault+0x71/0x57d arch/x86/mm/fault.c:1554 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1156 RIP: 0033:0x7f4c96bdc317 Code: 24 30 48 8b 40 08 48 89 44 24 70 48 8b 86 f8 02 00 00 48 85 c0 0f 84 fc 04 00 00 8b 96 f0 02 00 00 8b 8e f4 02 00 00 44 21 c2 <48> 8b 14 d0 4c 89 e8 48 d3 e8 48 89 c1 83 e1 3f 48 89 d0 48 d3 e8 RSP: 002b:00007ffe3534cd60 EFLAGS: 00010202 RAX: 00007f4c969b3ba8 RBX: 00007f4c96dea048 RCX: 000000000000000b RDX: 000000000000001f RSI: 00007f4c96df14c8 RDI: 000000000040178d RBP: 0000000000000001 R08: 0000000003f0b27f R09: 0000000000000005 R10: 0000000000000008 R11: 00007ffe3534cdb0 R12: 0000000000000007 R13: 00000000fc2c9fc5 R14: 0000000000000000 R15: 00007ffe3534cf38 Allocated by task 8899: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:497 slab_post_alloc_hook mm/slab.h:437 [inline] slab_alloc mm/slab.c:3326 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3488 kmem_cache_zalloc include/linux/slab.h:732 [inline] net_alloc net/core/net_namespace.c:386 [inline] copy_net_ns+0xed/0x340 net/core/net_namespace.c:426 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2692 __do_sys_unshare kernel/fork.c:2760 [inline] __se_sys_unshare kernel/fork.c:2758 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2758 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2559: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3698 net_free net/core/net_namespace.c:402 [inline] net_drop_ns.part.0+0x70/0x90 net/core/net_namespace.c:409 net_drop_ns net/core/net_namespace.c:408 [inline] cleanup_net+0x538/0x960 net/core/net_namespace.c:571 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff88806bbe0180 which belongs to the cache net_namespace of size 8640 The buggy address is located 568 bytes inside of 8640-byte region [ffff88806bbe0180, ffff88806bbe2340) The buggy address belongs to the page: page:ffffea0001aef800 refcount:1 mapcount:0 mapping:ffff88821b6f60c0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001bbca08 ffffea000173dc08 ffff88821b6f60c0 raw: 0000000000000000 ffff88806bbe0180 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88806bbe0280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806bbe0300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806bbe0380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806bbe0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806bbe0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================