================================================================== BUG: KASAN: use-after-free in atomic_read /./include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in refcount_inc_not_zero_checked+0x7c/0x280 /lib/refcount.c:123 Read of size 4 at addr ffff88808ee52080 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.2.0+ #35 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+0x1d8/0x2f8 /lib/dump_stack.c:113 print_address_description+0x75/0x5b0 /mm/kasan/report.c:351 __kasan_report+0x14b/0x1c0 /mm/kasan/report.c:482 kasan_report+0x26/0x50 /mm/kasan/common.c:612 check_memory_region_inline /mm/kasan/generic.c:182 [inline] check_memory_region+0x2cf/0x2e0 /mm/kasan/generic.c:192 __kasan_check_read+0x11/0x20 /mm/kasan/common.c:92 atomic_read /./include/asm-generic/atomic-instrumented.h:26 [inline] refcount_inc_not_zero_checked+0x7c/0x280 /lib/refcount.c:123 refcount_inc_checked+0x15/0x50 /lib/refcount.c:156 sock_hold /./include/net/sock.h:649 [inline] sk_add_node /./include/net/sock.h:701 [inline] nr_insert_socket /net/netrom/af_netrom.c:137 [inline] nr_rx_frame+0x17bc/0x1e40 /net/netrom/af_netrom.c:1023 nr_loopback_timer+0x6a/0x140 /net/netrom/nr_loopback.c:59 call_timer_fn+0xec/0x200 /kernel/time/timer.c:1322 expire_timers /kernel/time/timer.c:1366 [inline] __run_timers+0x7cd/0x9c0 /kernel/time/timer.c:1685 run_timer_softirq+0x4a/0x90 /kernel/time/timer.c:1698 __do_softirq+0x333/0x7c4 /./arch/x86/include/asm/paravirt.h:777 invoke_softirq /kernel/softirq.c:373 [inline] irq_exit+0x227/0x230 /kernel/softirq.c:413 exiting_irq /./arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x113/0x280 /arch/x86/kernel/apic/apic.c:1095 apic_timer_interrupt+0xf/0x20 /arch/x86/entry/entry_64.S:828 RIP: 0010:native_safe_halt+0xe/0x10 /./arch/x86/include/asm/irqflags.h:61 Code: 06 fa eb ae 89 d9 80 e1 07 80 c1 03 38 c1 7c ba 48 89 df e8 c4 41 06 fa eb b0 90 90 e9 07 00 00 00 0f 00 2d 76 67 56 00 fb f4 90 e9 07 00 00 00 0f 00 2d 66 67 56 00 f4 c3 90 90 55 48 89 e5 RSP: 0018:ffff8880a98cfd38 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11950db RBX: ffff8880a98bc340 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff812d193a RDI: ffff8880a98bcb78 RBP: ffff8880a98cfd40 R08: ffff8880a98bcb90 R09: ffffed1015317869 R10: ffffed1015317869 R11: 0000000000000000 R12: 0000000000000001 R13: 1ffff11015317868 R14: dffffc0000000000 R15: dffffc0000000000 arch_cpu_idle+0xa/0x10 /arch/x86/kernel/process.c:571 default_idle_call+0x59/0xa0 /kernel/sched/idle.c:94 cpuidle_idle_call /kernel/sched/idle.c:154 [inline] do_idle+0x180/0x780 /kernel/sched/idle.c:263 cpu_startup_entry+0x25/0x30 /kernel/sched/idle.c:354 start_secondary+0x3f4/0x490 /arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 /arch/x86/kernel/head_64.S:243 Allocated by task 0: save_stack /mm/kasan/common.c:69 [inline] set_track /mm/kasan/common.c:77 [inline] __kasan_kmalloc+0x11c/0x1b0 /mm/kasan/common.c:487 kasan_kmalloc+0x9/0x10 /mm/kasan/common.c:501 __do_kmalloc /mm/slab.c:3655 [inline] __kmalloc+0x254/0x340 /mm/slab.c:3664 kmalloc /./include/linux/slab.h:557 [inline] sk_prot_alloc+0xb0/0x290 /net/core/sock.c:1603 sk_alloc+0x38/0x950 /net/core/sock.c:1657 nr_make_new /net/netrom/af_netrom.c:476 [inline] nr_rx_frame+0xabc/0x1e40 /net/netrom/af_netrom.c:959 nr_loopback_timer+0x6a/0x140 /net/netrom/nr_loopback.c:59 call_timer_fn+0xec/0x200 /kernel/time/timer.c:1322 expire_timers /kernel/time/timer.c:1366 [inline] __run_timers+0x7cd/0x9c0 /kernel/time/timer.c:1685 run_timer_softirq+0x4a/0x90 /kernel/time/timer.c:1698 __do_softirq+0x333/0x7c4 /./arch/x86/include/asm/paravirt.h:777 Freed by task 4044: save_stack /mm/kasan/common.c:69 [inline] set_track /mm/kasan/common.c:77 [inline] __kasan_slab_free+0x12a/0x1e0 /mm/kasan/common.c:449 kasan_slab_free+0xe/0x10 /mm/kasan/common.c:457 __cache_free /mm/slab.c:3425 [inline] kfree+0x115/0x200 /mm/slab.c:3756 sk_prot_free /net/core/sock.c:1640 [inline] __sk_destruct+0x567/0x660 /net/core/sock.c:1726 sk_destruct /net/core/sock.c:1734 [inline] __sk_free+0x317/0x3e0 /net/core/sock.c:1745 sk_free /net/core/sock.c:1756 [inline] sock_put /./include/net/sock.h:1725 [inline] sock_efree+0x60/0x80 /net/core/sock.c:2042 skb_release_head_state+0x100/0x220 /net/core/skbuff.c:652 skb_release_all /net/core/skbuff.c:663 [inline] __kfree_skb+0x25/0x170 /net/core/skbuff.c:679 kfree_skb+0x6f/0xb0 /net/core/skbuff.c:697 nr_accept+0x4ef/0x650 /net/netrom/af_netrom.c:819 __sys_accept4+0x5bc/0x9a0 /net/socket.c:1750 __do_sys_accept /net/socket.c:1791 [inline] __se_sys_accept /net/socket.c:1788 [inline] __x64_sys_accept+0x7d/0x90 /net/socket.c:1788 do_syscall_64+0xfe/0x140 /arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808ee52000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of 2048-byte region [ffff88808ee52000, ffff88808ee52800) The buggy address belongs to the page: page:ffffea00023b9480 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0xffff88808ee53100 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001732108 ffffea00025f5588 ffff8880aa400e00 raw: ffff88808ee53100 ffff88808ee52000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808ee51f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808ee52000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808ee52080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808ee52100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808ee52180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================