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BUG: KASAN: slab-out-of-bounds in tcp_retransmit_timer+0x305e/0x3470 net/ipv4/tcp_timer.c:485
Read of size 8 at addr ffff88809de44338 by task swapper/1/0

CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.197-syzkaller #0
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+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 tcp_retransmit_timer+0x305e/0x3470 net/ipv4/tcp_timer.c:485
 tcp_write_timer_handler+0x5e6/0xa60 net/ipv4/tcp_timer.c:598
 tcp_write_timer+0x103/0x1b0 net/ipv4/tcp_timer.c:618
 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338
 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375
 __run_timers kernel/time/timer.c:1696 [inline]
 run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709
 __do_softirq+0x265/0x980 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x215/0x260 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: 48 89 df e8 a4 dc 7f f9 e9 2e ff ff ff 48 89 df e8 97 dc 7f f9 eb 82 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 24 12 4f 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 14 12 4f 00 f4 c3 90 90 41 56 41 55
RSP: 0018:ffff8880b5a9fd40 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff13e304c RBX: dffffc0000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff8880b5a86c44
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89f18250
R13: 1ffff11016b53fb2 R14: 0000000000000000 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
 default_idle+0x49/0x310 arch/x86/kernel/process.c:557
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x2ec/0x4b0 kernel/sched/idle.c:263
 cpu_startup_entry+0xc5/0xe0 kernel/sched/idle.c:369
 start_secondary+0x435/0x5c0 arch/x86/kernel/smpboot.c:271
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

Allocated by task 1946:
 kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 kernfs_iop_get_link fs/kernfs/symlink.c:136 [inline]
 kernfs_iop_get_link+0x61/0x6f0 fs/kernfs/symlink.c:127
 get_link fs/namei.c:1085 [inline]
 trailing_symlink+0x735/0x930 fs/namei.c:2264
 path_openat+0x91e/0x2df0 fs/namei.c:3539
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 1946:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 do_delayed_call include/linux/delayed_call.h:28 [inline]
 put_link fs/namei.c:883 [inline]
 step_into fs/namei.c:1773 [inline]
 do_last fs/namei.c:3386 [inline]
 path_openat+0xb09/0x2df0 fs/namei.c:3537
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809de44740
 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 1032 bytes to the left of
 4096-byte region [ffff88809de44740, ffff88809de45740)
The buggy address belongs to the page:
page:ffffea0002779100 count:1 mapcount:0 mapping:ffff88813bff0dc0 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea0000baae08 ffffea0001046b88 ffff88813bff0dc0
raw: 0000000000000000 ffff88809de44740 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809de44200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809de44280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88809de44300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                        ^
 ffff88809de44380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809de44400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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