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BUG: KASAN: slab-out-of-bounds in tcp_retransmit_timer+0x2d4c/0x3240 net/ipv4/tcp_timer.c:500
Read of size 8 at addr ffff88804ba762d0 by task kworker/u4:5/465

CPU: 1 PID: 465 Comm: kworker/u4:5 Not tainted 5.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fd lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 tcp_retransmit_timer+0x2d4c/0x3240 net/ipv4/tcp_timer.c:500
 tcp_write_timer_handler+0x79b/0xa60 net/ipv4/tcp_timer.c:611
 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:631
 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413
 expire_timers kernel/time/timer.c:1458 [inline]
 __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755
 __run_timers kernel/time/timer.c:1736 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1768
 __do_softirq+0x1f8/0xb23 kernel/softirq.c:298
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x9b/0xd0 arch/x86/kernel/irq_64.c:77
 do_softirq kernel/softirq.c:343 [inline]
 do_softirq+0x154/0x1b0 kernel/softirq.c:330
 __local_bh_enable_ip+0x196/0x1f0 kernel/softirq.c:195
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 get_next_corpse net/netfilter/nf_conntrack_core.c:2226 [inline]
 nf_ct_iterate_cleanup+0x9e/0x330 net/netfilter/nf_conntrack_core.c:2249
 nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2334 [inline]
 nf_ct_iterate_cleanup_net+0x113/0x170 net/netfilter/nf_conntrack_core.c:2319
 masq_device_event+0xae/0xe0 net/netfilter/nf_nat_masquerade.c:88
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2033
 call_netdevice_notifiers_extack net/core/dev.c:2045 [inline]
 call_netdevice_notifiers net/core/dev.c:2059 [inline]
 dev_close_many+0x30b/0x650 net/core/dev.c:1634
 rollback_registered_many+0x3a8/0x1250 net/core/dev.c:9261
 unregister_netdevice_many.part.0+0x1a/0x2f0 net/core/dev.c:10429
 unregister_netdevice_many net/core/dev.c:10428 [inline]
 default_device_exit_batch+0x30c/0x3d0 net/core/dev.c:10912
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:189
 cleanup_net+0x4ea/0xa00 net/core/net_namespace.c:603
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Allocated by task 3924:
 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:518 [inline]
 slab_alloc mm/slab.c:3316 [inline]
 kmem_cache_alloc+0x13a/0x3f0 mm/slab.c:3486
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
 getname_flags fs/namei.c:2646 [inline]
 user_path_at_empty+0xa1/0x100 fs/namei.c:2646
 user_path_at include/linux/namei.h:59 [inline]
 vfs_statx+0x14e/0x390 fs/stat.c:202
 vfs_lstat include/linux/fs.h:3178 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:374
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 3924:
 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:3422 [inline]
 kmem_cache_free.part.0+0x74/0x1e0 mm/slab.c:3697
 putname+0xe1/0x120 fs/namei.c:259
 filename_lookup+0x3b1/0x560 fs/namei.c:2376
 user_path_at include/linux/namei.h:59 [inline]
 vfs_statx+0x14e/0x390 fs/stat.c:202
 vfs_lstat include/linux/fs.h:3178 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:374
 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 ffff88804ba76440
 which belongs to the cache names_cache of size 4096
The buggy address is located 368 bytes to the left of
 4096-byte region [ffff88804ba76440, ffff88804ba77440)
The buggy address belongs to the page:
page:000000009d94ec35 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4ba76
head:000000009d94ec35 order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea00010e3408 ffffea0002a36788 ffff88821bc47a00
raw: 0000000000000000 ffff88804ba76440 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804ba76180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88804ba76200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804ba76280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff88804ba76300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88804ba76380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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