================================================================== 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 ffff88808e459300 by task syz-executor.1/23365 CPU: 0 PID: 23365 Comm: syz-executor.1 Not tainted 5.3.0-rc2+ #95 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:tomoyo_domain_quota_is_ok+0x300/0x540 security/tomoyo/util.c:1069 Code: ff 45 31 e4 e8 61 6f 6c fe 44 89 e0 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d c3 41 bd 01 00 00 00 31 db e8 42 6f 6c fe 89 d9 <44> 89 ee 31 ff d3 fe 83 e6 01 41 89 f7 e8 ae 70 6c fe 45 85 ff 74 RSP: 0018:ffff888090ef7710 EFLAGS: 00000212 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: 0000000000000002 RCX: 0000000000000002 RDX: 0000000000004646 RSI: ffffffff8306301e RDI: 0000000000000001 RBP: ffff888090ef7750 R08: ffff888095528280 R09: ffffed10121deef7 R10: ffffed10121deef6 R11: 0000000000000000 R12: ffff88809423c300 R13: 0000000000000002 R14: 000000000000015b R15: 0000000000000001 tomoyo_supervisor+0x2e8/0xef0 security/tomoyo/common.c:2087 tomoyo_audit_net_log security/tomoyo/network.c:367 [inline] tomoyo_audit_inet_log+0x26a/0x340 security/tomoyo/network.c:393 tomoyo_inet_entry security/tomoyo/network.c:484 [inline] tomoyo_check_inet_address security/tomoyo/network.c:532 [inline] tomoyo_check_inet_address+0x62f/0x740 security/tomoyo/network.c:501 tomoyo_socket_sendmsg_permission+0x2d5/0x3cb security/tomoyo/network.c:774 tomoyo_socket_sendmsg+0x26/0x30 security/tomoyo/tomoyo.c:486 security_socket_sendmsg+0x77/0xc0 security/security.c:1973 sock_sendmsg+0x45/0x130 net/socket.c:654 __sys_sendto+0x262/0x380 net/socket.c:1952 __do_sys_sendto net/socket.c:1964 [inline] __se_sys_sendto net/socket.c:1960 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1960 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ff730fc7c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459829 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 000000000075bfc8 R08: 0000000020000240 R09: 000000000000001c R10: 0000000000008000 R11: 0000000000000246 R12: 00007ff730fc86d4 R13: 00000000004c77d9 R14: 00000000004dcf90 R15: 00000000ffffffff Allocated by task 23365: 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 23366: 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 ffff88808e459280 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of 2048-byte region [ffff88808e459280, ffff88808e459a80) The buggy address belongs to the page: page:ffffea0002391600 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0xffff88808e458180 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001a24d88 ffffea00023d2988 ffff8880aa400e00 raw: ffff88808e458180 ffff88808e458180 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808e459200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808e459280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808e459300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808e459380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808e459400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================