syzbot

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BUG: KASAN: use-after-free in __dev_remove_pack+0x305/0x3b0 net/core/dev.c:436
Read of size 8 at addr ffff8801cde81528 by task syzkaller313808/3118

CPU: 1 PID: 3118 Comm: syzkaller313808 Not tainted 4.13.0+ #79
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x24e/0x340 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 __dev_remove_pack+0x305/0x3b0 net/core/dev.c:436
 __fanout_unlink net/packet/af_packet.c:1525 [inline]
 __unregister_prot_hook+0x211/0x280 net/packet/af_packet.c:367
 unregister_prot_hook net/packet/af_packet.c:385 [inline]
 packet_release+0x8bb/0xd70 net/packet/af_packet.c:3006
 sock_release+0x8d/0x1e0 net/socket.c:597
 sock_close+0x16/0x20 net/socket.c:1126
 __fput+0x333/0x7f0 fs/file_table.c:210
 ____fput+0x15/0x20 fs/file_table.c:246
 task_work_run+0x199/0x270 kernel/task_work.c:112
 exit_task_work include/linux/task_work.h:21 [inline]
 do_exit+0xa52/0x1b40 kernel/exit.c:865
 do_group_exit+0x149/0x400 kernel/exit.c:968
 SYSC_exit_group kernel/exit.c:979 [inline]
 SyS_exit_group+0x1d/0x20 kernel/exit.c:977
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x446309
RSP: 002b:00007ffd74db1888 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000000446309
RDX: 0000000000444a61 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000082 R08: 00000000006da1c0 R09: 0000000000000000
R10: 00000000006da144 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ffd74db182f R14: 00007f728b4189c0 R15: 0000000000000000

Allocated by task 3154:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:666 [inline]
 fanout_add+0xa50/0x1190 net/packet/af_packet.c:1733
 packet_setsockopt+0xfdc/0x1e80 net/packet/af_packet.c:3795
 SYSC_setsockopt net/socket.c:1852 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1831
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 3118:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xca/0x250 mm/slab.c:3820
 packet_release+0xa8f/0xd70 net/packet/af_packet.c:3033
 sock_release+0x8d/0x1e0 net/socket.c:597
 sock_close+0x16/0x20 net/socket.c:1126
 __fput+0x333/0x7f0 fs/file_table.c:210
 ____fput+0x15/0x20 fs/file_table.c:246
 task_work_run+0x199/0x270 kernel/task_work.c:112
 exit_task_work include/linux/task_work.h:21 [inline]
 do_exit+0xa52/0x1b40 kernel/exit.c:865
 do_group_exit+0x149/0x400 kernel/exit.c:968
 SYSC_exit_group kernel/exit.c:979 [inline]
 SyS_exit_group+0x1d/0x20 kernel/exit.c:977
 entry_SYSCALL_64_fastpath+0x1f/0xbe

The buggy address belongs to the object at ffff8801cde80c80
 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 2216 bytes inside of
 4096-byte region [ffff8801cde80c80, ffff8801cde81c80)
The buggy address belongs to the page:
page:ffffea000737a000 count:1 mapcount:0 mapping:ffff8801cde80c80 index:0x0 compound_mapcount: 0
flags: 0x200000000008100(slab|head)
raw: 0200000000008100 ffff8801cde80c80 0000000000000000 0000000100000001
raw: ffffea0007379fa0 ffffea000737a220 ffff8801dac00dc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cde81400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801cde81480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801cde81500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff8801cde81580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801cde81600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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