================================================================== 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+0x81/0x200 lib/refcount.c:123 Read of size 4 at addr ffff8880a0dbae00 by task udevd/5072 CPU: 0 PID: 5072 Comm: udevd Not tainted 5.2.0+ #67 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+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x17 mm/kasan/common.c:612 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 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+0x81/0x200 lib/refcount.c:123 refcount_inc_checked+0x17/0x70 lib/refcount.c:156 sock_hold include/net/sock.h:649 [inline] sk_add_node include/net/sock.h:701 [inline] nr_insert_socket+0x2d/0xe0 net/netrom/af_netrom.c:137 nr_rx_frame+0x1605/0x1e73 net/netrom/af_netrom.c:1023 nr_loopback_timer+0x7b/0x170 net/netrom/nr_loopback.c:59 call_timer_fn+0x1ac/0x780 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+0x697/0x17a0 kernel/time/timer.c:1698 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline] RIP: 0010:kmem_cache_free+0xab/0x320 mm/slab.c:3694 Code: e8 1a 27 00 00 84 c0 74 77 41 f7 c6 00 02 00 00 74 4f e8 d8 b3 cb ff 48 83 3d 20 a3 26 07 00 0f 84 fa 01 00 00 4c 89 f7 57 9d <0f> 1f 44 00 00 4c 8b 6d 08 0f 1f 44 00 00 65 8b 05 40 46 55 7e 83 RSP: 0018:ffff8880a857f928 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000007 RBX: ffff888091b6c2a0 RCX: 0000000000000006 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffff8880a857f948 R08: 1ffffffff14a7750 R09: fffffbfff14a7751 R10: fffffbfff14a7750 R11: ffffffff8a53ba87 R12: ffff88821bc42700 R13: ffffffff81a222ca R14: 0000000000000286 R15: ffff88809925b2f8 anon_vma_chain_free mm/rmap.c:134 [inline] unlink_anon_vmas+0x2ba/0x860 mm/rmap.c:401 free_pgtables+0x1af/0x2f0 mm/memory.c:395 exit_mmap+0x2c9/0x530 mm/mmap.c:3146 __mmput kernel/fork.c:1064 [inline] mmput+0x179/0x4d0 kernel/fork.c:1085 exec_mmap fs/exec.c:1047 [inline] flush_old_exec+0x8c2/0x1e90 fs/exec.c:1280 load_elf_binary+0xa64/0x5730 fs/binfmt_elf.c:867 search_binary_handler fs/exec.c:1658 [inline] search_binary_handler+0x16d/0x570 fs/exec.c:1635 exec_binprm fs/exec.c:1701 [inline] __do_execve_file.isra.0+0x1333/0x2340 fs/exec.c:1821 do_execveat_common fs/exec.c:1868 [inline] do_execve fs/exec.c:1885 [inline] __do_sys_execve fs/exec.c:1961 [inline] __se_sys_execve fs/exec.c:1956 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1956 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f6a9e3aa207 Code: Bad RIP value. RSP: 002b:00007ffde36972b8 EFLAGS: 00000206 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f6a9e3aa207 RDX: 00000000009d5e80 RSI: 00007ffde36973b0 RDI: 00007ffde36983c0 RBP: 0000000000625500 R08: 00000000000059dc R09: 00000000000059dc R10: 0000000000000000 R11: 0000000000000206 R12: 00000000009d5e80 R13: 0000000000000007 R14: 00000000009bd250 R15: 0000000000000005 Allocated by task 5072: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:487 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:460 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:501 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x163/0x770 mm/slab.c:3664 kmalloc include/linux/slab.h:557 [inline] sk_prot_alloc+0x23a/0x310 net/core/sock.c:1603 sk_alloc+0x39/0xf70 net/core/sock.c:1657 nr_make_new net/netrom/af_netrom.c:476 [inline] nr_rx_frame+0x733/0x1e73 net/netrom/af_netrom.c:959 nr_loopback_timer+0x7b/0x170 net/netrom/nr_loopback.c:59 call_timer_fn+0x1ac/0x780 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+0x697/0x17a0 kernel/time/timer.c:1698 __do_softirq+0x262/0x98c kernel/softirq.c:292 Freed by task 5068: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:449 kasan_slab_free+0xe/0x10 mm/kasan/common.c:457 __cache_free mm/slab.c:3425 [inline] kfree+0x10a/0x2c0 mm/slab.c:3756 sk_prot_free net/core/sock.c:1640 [inline] __sk_destruct+0x4f7/0x6e0 net/core/sock.c:1726 sk_destruct+0x86/0xa0 net/core/sock.c:1734 __sk_free+0xfb/0x360 net/core/sock.c:1745 sk_free+0x42/0x50 net/core/sock.c:1756 sock_put include/net/sock.h:1725 [inline] sock_efree+0x61/0x80 net/core/sock.c:2042 skb_release_head_state+0xeb/0x250 net/core/skbuff.c:652 skb_release_all+0x16/0x60 net/core/skbuff.c:663 __kfree_skb net/core/skbuff.c:679 [inline] kfree_skb net/core/skbuff.c:697 [inline] kfree_skb+0x101/0x3c0 net/core/skbuff.c:691 nr_accept+0x56e/0x700 net/netrom/af_netrom.c:819 __sys_accept4+0x34e/0x6a0 net/socket.c:1754 __do_sys_accept4 net/socket.c:1789 [inline] __se_sys_accept4 net/socket.c:1786 [inline] __x64_sys_accept4+0x97/0xf0 net/socket.c:1786 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a0dbad80 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of 2048-byte region [ffff8880a0dbad80, ffff8880a0dbb580) The buggy address belongs to the page: page:ffffea0002836e80 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001c8bb88 ffffea000180d108 ffff8880aa400e00 raw: 0000000000000000 ffff8880a0dba500 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a0dbad00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a0dbad80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a0dbae00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a0dbae80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a0dbaf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================