syzbot

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refcount_t: saturated; leaking memory.
WARNING: lib/refcount.c:22 at refcount_warn_saturate+0x8c/0x110 lib/refcount.c:22, CPU#0: syz.6.4051/19298
Modules linked in:
CPU: 0 UID: 0 PID: 19298 Comm: syz.6.4051 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:refcount_warn_saturate+0x8c/0x110 lib/refcount.c:22
Code: 75 68 e8 d7 1b 03 fd 48 8d 3d 80 2a f8 0a 67 48 0f b9 3a eb 66 85 db 74 3e 83 fb 01 75 4c e8 bb 1b 03 fd 48 8d 3d 74 2a f8 0a <67> 48 0f b9 3a eb 4a e8 a8 1b 03 fd 48 8d 3d 71 2a f8 0a 67 48 0f
RSP: 0018:ffffc90004cc7858 EFLAGS: 00010283
RAX: ffffffff84c21cb5 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc90018934000 RSI: 00000000000007d2 RDI: ffffffff8fba4730
RBP: 00000000ffffffff R08: ffff888037be3e00 R09: 0000000000000005
R10: 0000000000000100 R11: 0000000000000004 R12: ffff88802ca02018
R13: ffffffff99a8aa60 R14: ffff88802ca02010 R15: ffff88802ca02000
FS:  00007f25413466c0(0000) GS:ffff888125c49000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c25352e CR3: 000000005bc9c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __refcount_add include/linux/refcount.h:-1 [inline]
 __refcount_inc include/linux/refcount.h:366 [inline]
 refcount_inc include/linux/refcount.h:383 [inline]
 kref_get include/linux/kref.h:45 [inline]
 dvb_device_get drivers/media/dvb-core/dvbdev.c:621 [inline]
 dvb_device_open+0x30a/0x350 drivers/media/dvb-core/dvbdev.c:106
 chrdev_open+0x4dc/0x600 fs/char_dev.c:411
 do_dentry_open+0x849/0x1420 fs/open.c:947
 vfs_open+0x3b/0x350 fs/open.c:1052
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2e60/0x3850 fs/namei.c:4863
 do_file_open+0x23e/0x4a0 fs/namei.c:4892
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f25430ae68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f2541345b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f25413466c0 RCX: 00007f25430ae68e
RDX: 0000000000040002 RSI: 00007f2541345c00 RDI: ffffffffffffff9c
RBP: 00007f2541345c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f2543376038 R14: 00007f2543375fa0 R15: 00007ffffed696e8
 </TASK>
----------------
Code disassembly (best guess):
   0:	75 68                	jne    0x6a
   2:	e8 d7 1b 03 fd       	call   0xfd031bde
   7:	48 8d 3d 80 2a f8 0a 	lea    0xaf82a80(%rip),%rdi        # 0xaf82a8e
   e:	67 48 0f b9 3a       	ud1    (%edx),%rdi
  13:	eb 66                	jmp    0x7b
  15:	85 db                	test   %ebx,%ebx
  17:	74 3e                	je     0x57
  19:	83 fb 01             	cmp    $0x1,%ebx
  1c:	75 4c                	jne    0x6a
  1e:	e8 bb 1b 03 fd       	call   0xfd031bde
  23:	48 8d 3d 74 2a f8 0a 	lea    0xaf82a74(%rip),%rdi        # 0xaf82a9e
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	eb 4a                	jmp    0x7b
  31:	e8 a8 1b 03 fd       	call   0xfd031bde
  36:	48 8d 3d 71 2a f8 0a 	lea    0xaf82a71(%rip),%rdi        # 0xaf82aae
  3d:	67                   	addr32
  3e:	48                   	rex.W
  3f:	0f                   	.byte 0xf