8021q: adding VLAN 0 to HW filter on device batadv0
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
==================================================================
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in refcount_inc_not_zero_checked+0x7b/0x200 lib/refcount.c:120
Read of size 4 at addr ffff88809efb4e40 by task syz-executor303/7350

CPU: 1 PID: 7350 Comm: syz-executor303 Not tainted 4.19.67 #41
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x123/0x190 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 refcount_inc_not_zero_checked+0x7b/0x200 lib/refcount.c:120
 refcount_inc_checked+0x17/0x70 lib/refcount.c:153
 sock_hold include/net/sock.h:647 [inline]
 nr_release+0x62/0x3b0 net/netrom/af_netrom.c:523
 __sock_release+0xce/0x2a0 net/socket.c:579
 sock_close+0x1b/0x30 net/socket.c:1140
 __fput+0x2dd/0x8b0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x994/0x2fa0 kernel/exit.c:876
 do_group_exit+0x135/0x370 kernel/exit.c:979
 get_signal+0x3ec/0x1fc0 kernel/signal.c:2574
 do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446359
Code: Bad RIP value.
RSP: 002b:00007fff611671a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000120
RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 0000000000446359
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000003 R08: 0000000301bbbbbb R09: 0000000301bbbbbb
R10: 0000000000000800 R11: 0000000000000246 R12: 0000000001a09850
R13: 000000000000000e R14: 0000000000000000 R15: 0000000000000000

Allocated by task 7350:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc+0x15d/0x750 mm/slab.c:3736
 kmalloc include/linux/slab.h:520 [inline]
 sk_prot_alloc+0x19c/0x2e0 net/core/sock.c:1466
 sk_alloc+0x39/0xf70 net/core/sock.c:1520
 nr_create+0xb9/0x5e0 net/netrom/af_netrom.c:436
 __sock_create+0x3d8/0x730 net/socket.c:1276
 sock_create net/socket.c:1316 [inline]
 __sys_socket+0x103/0x220 net/socket.c:1346
 __do_sys_socket net/socket.c:1355 [inline]
 __se_sys_socket net/socket.c:1353 [inline]
 __x64_sys_socket+0x73/0xb0 net/socket.c:1353
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7350:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcf/0x220 mm/slab.c:3822
 sk_prot_free net/core/sock.c:1503 [inline]
 __sk_destruct+0x4ef/0x6d0 net/core/sock.c:1585
 sk_destruct+0x7b/0x90 net/core/sock.c:1593
 __sk_free+0xce/0x300 net/core/sock.c:1604
 sk_free+0x42/0x50 net/core/sock.c:1615
 sock_put include/net/sock.h:1702 [inline]
 nr_release+0x332/0x3b0 net/netrom/af_netrom.c:557
 __sock_release+0xce/0x2a0 net/socket.c:579
 sock_close+0x1b/0x30 net/socket.c:1140
 __fput+0x2dd/0x8b0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x994/0x2fa0 kernel/exit.c:876
 do_group_exit+0x135/0x370 kernel/exit.c:979
 get_signal+0x3ec/0x1fc0 kernel/signal.c:2574
 do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809efb4dc0
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 128 bytes inside of
 2048-byte region [ffff88809efb4dc0, ffff88809efb55c0)
The buggy address belongs to the page:
page:ffffea00027bed00 count:1 mapcount:0 mapping:ffff88812c3f0c40 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)
raw: 01fffc0000008100 ffffea00021b3308 ffffea00025d6b08 ffff88812c3f0c40
raw: 0000000000000000 ffff88809efb4540 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809efb4d00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88809efb4d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff88809efb4e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88809efb4e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809efb4f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================