==================================================================
BUG: KASAN: slab-out-of-bounds in tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline]
BUG: KASAN: slab-out-of-bounds in tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596
Read of size 4 at addr ffff8880a7a1e7d0 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0+ #67
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+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
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
 tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline]
 tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596
 tcp_write_timer+0xa8/0x1e0 net/ipv4/tcp_timer.c:612
 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
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: 68 96 73 fa eb 8a 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d e4 26 4f 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d d4 26 4f 00 fb f4 <c3> 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 be 57 27 fa e8 79
RSP: 0018:ffffffff88c07ce8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11a5e05 RBX: ffffffff88c7a1c0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff88c7aa4c
RBP: ffffffff88c07d18 R08: ffffffff88c7a1c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffffff89a4f7b8 R14: 0000000000000000 R15: 0000000000000000
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571
 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x413/0x760 kernel/sched/idle.c:263
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
 rest_init+0x245/0x37b init/main.c:451
 arch_call_rest_init+0xe/0x1b
 start_kernel+0x912/0x951 init/main.c:785
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:472
 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:453
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

Allocated by task 387:
 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]
 tomoyo_realpath_from_path+0xcd/0x7b0 security/tomoyo/realpath.c:277
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x2a8/0x3f0 security/tomoyo/file.c:771
 tomoyo_file_open security/tomoyo/tomoyo.c:319 [inline]
 tomoyo_file_open+0xa9/0xd0 security/tomoyo/tomoyo.c:314
 security_file_open+0x71/0x300 security/security.c:1457
 do_dentry_open+0x373/0x1250 fs/open.c:765
 vfs_open+0xa0/0xd0 fs/open.c:887
 do_last fs/namei.c:3416 [inline]
 path_openat+0x10e9/0x4630 fs/namei.c:3533
 do_filp_open+0x1a1/0x280 fs/namei.c:3563
 do_sys_open+0x3fe/0x5d0 fs/open.c:1070
 __do_sys_open fs/open.c:1088 [inline]
 __se_sys_open fs/open.c:1083 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1083
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 387:
 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
 tomoyo_realpath_from_path+0x1de/0x7b0 security/tomoyo/realpath.c:319
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x2a8/0x3f0 security/tomoyo/file.c:771
 tomoyo_file_open security/tomoyo/tomoyo.c:319 [inline]
 tomoyo_file_open+0xa9/0xd0 security/tomoyo/tomoyo.c:314
 security_file_open+0x71/0x300 security/security.c:1457
 do_dentry_open+0x373/0x1250 fs/open.c:765
 vfs_open+0xa0/0xd0 fs/open.c:887
 do_last fs/namei.c:3416 [inline]
 path_openat+0x10e9/0x4630 fs/namei.c:3533
 do_filp_open+0x1a1/0x280 fs/namei.c:3563
 do_sys_open+0x3fe/0x5d0 fs/open.c:1070
 __do_sys_open fs/open.c:1088 [inline]
 __se_sys_open fs/open.c:1083 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1083
 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 ffff8880a7a1ec40
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1136 bytes to the left of
 4096-byte region [ffff8880a7a1ec40, ffff8880a7a1fc40)
The buggy address belongs to the page:
page:ffffea00029e8780 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea0001479808 ffffea00021a0788 ffff8880aa402000
raw: 0000000000000000 ffff8880a7a1ec40 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a7a1e680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a7a1e700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a7a1e780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff8880a7a1e800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a7a1e880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================