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BUG: KASAN: slab-out-of-bounds in tcp_retransmit_timer+0x2a66/0x2e80 net/ipv4/tcp_timer.c:500
Read of size 8 at addr ffff888065918550 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc5-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+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:382
 __kasan_report.cold+0x20/0x38 mm/kasan/report.c:511
 kasan_report+0x33/0x50 mm/kasan/common.c:625
 tcp_retransmit_timer+0x2a66/0x2e80 net/ipv4/tcp_timer.c:500
 tcp_write_timer_handler+0x686/0x8a0 net/ipv4/tcp_timer.c:611
 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:631
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1773 [inline]
 __run_timers kernel/time/timer.c:1740 [inline]
 run_timer_softirq+0x623/0x1600 kernel/time/timer.c:1786
 __do_softirq+0x26c/0x9f7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x192/0x1d0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:546 [inline]
 smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1140
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: cc cc cc cc cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 34 68 53 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 24 68 53 00 fb f4 <c3> cc 41 56 41 55 41 54 55 53 e8 c3 e6 8b f9 e8 6e 24 c5 fb 0f 1f
RSP: 0018:ffffffff89807d98 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff132980f RBX: ffffffff89886540 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff89886e04
RBP: dffffc0000000000 R08: ffffffff89886540 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff1310ca8
R13: 0000000000000000 R14: ffffffff8a8a3780 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:144 [inline]
 default_idle+0x49/0x350 arch/x86/kernel/process.c:697
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x393/0x690 kernel/sched/idle.c:269
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
 start_kernel+0x97d/0x9b7 init/main.c:1040
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

Allocated by task 31520:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc mm/kasan/common.c:495 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468
 slab_post_alloc_hook mm/slab.h:586 [inline]
 slab_alloc mm/slab.c:3320 [inline]
 kmem_cache_alloc+0x11b/0x740 mm/slab.c:3484
 getname_flags fs/namei.c:138 [inline]
 getname_flags+0xd2/0x5b0 fs/namei.c:128
 do_sys_openat2+0x3fc/0x7d0 fs/open.c:1142
 do_sys_open+0xc3/0x140 fs/open.c:1164
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 31520:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 kasan_set_free_info mm/kasan/common.c:317 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456
 __cache_free mm/slab.c:3426 [inline]
 kmem_cache_free+0x7f/0x320 mm/slab.c:3694
 putname+0xe1/0x120 fs/namei.c:259
 do_sys_openat2+0x467/0x7d0 fs/open.c:1157
 do_sys_open+0xc3/0x140 fs/open.c:1164
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff888065918e00
 which belongs to the cache names_cache of size 4096
The buggy address is located 2224 bytes to the left of
 4096-byte region [ffff888065918e00, ffff888065919e00)
The buggy address belongs to the page:
page:ffffea0001964600 refcount:1 mapcount:0 mapping:00000000ecfae5d7 index:0x0 head:ffffea0001964600 order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea00015f9208 ffffea00017a4f88 ffff8880aa1ec000
raw: 0000000000000000 ffff888065918e00 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888065918400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888065918480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888065918500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff888065918580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888065918600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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