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BUG: KASAN: slab-out-of-bounds in tcp_probe_timer net/ipv4/tcp_timer.c:372 [inline]
BUG: KASAN: slab-out-of-bounds in tcp_write_timer_handler+0x9d0/0xa60 net/ipv4/tcp_timer.c:615
Read of size 4 at addr ffff88805d1c8744 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc5-next-20200916-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+0x198/0x1fb lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 tcp_probe_timer net/ipv4/tcp_timer.c:372 [inline]
 tcp_write_timer_handler+0x9d0/0xa60 net/ipv4/tcp_timer.c:615
 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:631
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1413
 expire_timers kernel/time/timer.c:1458 [inline]
 __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1755
 __run_timers kernel/time/timer.c:1736 [inline]
 run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768
 __do_softirq+0x202/0xa42 kernel/softirq.c:298
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:786
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu kernel/softirq.c:423 [inline]
 irq_exit_rcu+0x235/0x280 kernel/softirq.c:435
 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: ff 4c 89 ef e8 f3 e7 ae f9 e9 8e fe ff ff 48 89 df e8 e6 e7 ae f9 eb 8a cc cc cc cc e9 07 00 00 00 0f 00 2d e4 4a 64 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d d4 4a 64 00 f4 c3 cc cc 55 53 e8 e9
RSP: 0018:ffffffff89c07cd8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff15cb689
RDX: ffffffff89c9b040 RSI: ffffffff88047e60 RDI: 0000000000000000
RBP: ffff88821af07864 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88821af07864
R13: 1ffffffff1380fa5 R14: ffff88821af07865 R15: 0000000000000001
 arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline]
 acpi_safe_halt+0x95/0x180 drivers/acpi/processor_idle.c:111
 acpi_idle_do_entry+0x15c/0x1b0 drivers/acpi/processor_idle.c:524
 acpi_idle_enter+0x403/0xac0 drivers/acpi/processor_idle.c:650
 cpuidle_enter_state+0x150/0xa70 drivers/cpuidle/cpuidle.c:243
 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:355
 call_cpuidle kernel/sched/idle.c:132 [inline]
 cpuidle_idle_call kernel/sched/idle.c:213 [inline]
 do_idle+0x48e/0x730 kernel/sched/idle.c:273
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:369
 start_kernel+0x490/0x4b1 init/main.c:1048
 secondary_startup_64_no_verify+0xa6/0xab

Allocated by task 3916:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 slab_post_alloc_hook mm/slab.h:514 [inline]
 slab_alloc mm/slab.c:3310 [inline]
 kmem_cache_alloc+0x162/0x500 mm/slab.c:3480
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
 getname_flags include/linux/audit.h:320 [inline]
 getname+0x8e/0xd0 fs/namei.c:209
 do_sys_openat2+0xf5/0x420 fs/open.c:1162
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_open fs/open.c:1192 [inline]
 __se_sys_open fs/open.c:1188 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1188
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 3916:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
 __cache_free mm/slab.c:3416 [inline]
 kmem_cache_free.part.0+0x74/0x1d0 mm/slab.c:3691
 putname+0xe1/0x120 fs/namei.c:259
 do_sys_openat2+0x153/0x420 fs/open.c:1177
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_open fs/open.c:1192 [inline]
 __se_sys_open fs/open.c:1188 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1188
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88805d1c8b80
 which belongs to the cache names_cache of size 4096
The buggy address is located 1084 bytes to the left of
 4096-byte region [ffff88805d1c8b80, ffff88805d1c9b80)
The buggy address belongs to the page:
page:00000000ca74db37 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d1c8
head:00000000ca74db37 order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea000154e908 ffffea0001582e08 ffff8880aa223c00
raw: 0000000000000000 ffff88805d1c8b80 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88805d1c8600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805d1c8680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88805d1c8700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff88805d1c8780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805d1c8800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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