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BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
BUG: KASAN: use-after-free in refcount_inc_not_zero_checked+0x3d/0x200 lib/refcount.c:123
Read of size 4 at addr ffff888099770080 by task syz-executor.2/31220

CPU: 1 PID: 31220 Comm: syz-executor.2 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 print_address_description+0x75/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 check_memory_region_inline mm/kasan/generic.c:182 [inline]
 check_memory_region+0x2cf/0x2e0 mm/kasan/generic.c:192
 __kasan_check_read+0x11/0x20 mm/kasan/common.c:92
 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
 refcount_inc_not_zero_checked+0x3d/0x200 lib/refcount.c:123
 refcount_inc_checked+0x15/0x50 lib/refcount.c:156
 sock_hold include/net/sock.h:649 [inline]
 nr_release+0x59/0x390 net/netrom/af_netrom.c:498
 __sock_release net/socket.c:590 [inline]
 sock_close+0xe1/0x260 net/socket.c:1268
 __fput+0x2e4/0x740 fs/file_table.c:280
 ____fput+0x15/0x20 fs/file_table.c:313
 task_work_run+0x17e/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
 prepare_exit_to_usermode+0x459/0x580 arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274
 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413db1
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffd35447630 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000413db1
RDX: 0000000000000000 RSI: ffffffff8778c9ae RDI: 0000000000000007
RBP: 0000000000000001 R08: ffffffff813674df R09: 0000000001065b13
R10: 00007ffd35447710 R11: 0000000000000293 R12: 000000000075c9a0
R13: 000000000075c9a0 R14: 0000000000762710 R15: 000000000075c124

Allocated by task 31227:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc+0x254/0x340 mm/slab.c:3664
 kmalloc include/linux/slab.h:561 [inline]
 sk_prot_alloc+0xb0/0x290 net/core/sock.c:1605
 sk_alloc+0x38/0x950 net/core/sock.c:1659
 nr_create+0xa7/0x510 net/netrom/af_netrom.c:411
 __sock_create+0x5cc/0x910 net/socket.c:1418
 sock_create net/socket.c:1469 [inline]
 __sys_socket+0xe7/0x2e0 net/socket.c:1511
 __do_sys_socket net/socket.c:1520 [inline]
 __se_sys_socket net/socket.c:1518 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1518
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 31220:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x115/0x200 mm/slab.c:3756
 sk_prot_free net/core/sock.c:1642 [inline]
 __sk_destruct+0x523/0x620 net/core/sock.c:1726
 sk_destruct net/core/sock.c:1741 [inline]
 __sk_free+0x35d/0x430 net/core/sock.c:1752
 sk_free+0x2a/0x40 net/core/sock.c:1763
 sock_put include/net/sock.h:1730 [inline]
 nr_release+0x1d2/0x390 net/netrom/af_netrom.c:532
 __sock_release net/socket.c:590 [inline]
 sock_close+0xe1/0x260 net/socket.c:1268
 __fput+0x2e4/0x740 fs/file_table.c:280
 ____fput+0x15/0x20 fs/file_table.c:313
 task_work_run+0x17e/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
 prepare_exit_to_usermode+0x459/0x580 arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274
 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888099770000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 2048-byte region [ffff888099770000, ffff888099770800)
The buggy address belongs to the page:
page:ffffea000265dc00 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea000115ba08 ffffea000223b588 ffff8880aa400e00
raw: 0000000000000000 ffff888099770000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809976ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888099770000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888099770080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888099770100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888099770180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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