------------[ cut here ]------------
WARNING: CPU: 0 PID: 5330 at fs/udf/truncate.c:224 udf_truncate_extents+0xd4c/0xec0 fs/udf/truncate.c:224
Modules linked in:
CPU: 0 UID: 0 PID: 5330 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:udf_truncate_extents+0xd4c/0xec0 fs/udf/truncate.c:224
Code: 98 10 0f 48 3b 84 24 80 01 00 00 75 77 44 89 e0 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 9b 31 00 08 cc e8 75 dd 83 fe 90 <0f> 0b 90 eb 88 44 89 e9 80 e1 07 38 c1 0f 8c e4 f3 ff ff 4c 89 ef
RSP: 0000:ffffc9000d357080 EFLAGS: 00010293
RAX: ffffffff833a47cb RBX: 1ffff1100a50319c RCX: ffff88801f52c880
RDX: 0000000000000000 RSI: 0000000007f9b262 RDI: 0000000000000000
RBP: ffffc9000d357250 R08: ffff88801f52c880 R09: 0000000000000002
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000007f9b200 R14: 0000000008000c62 R15: 0000000007f9b262
FS:  0000555580a2a500(0000) GS:ffff88808d972000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000514ff8 CR3: 0000000042543000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 udf_do_extend_file+0xacf/0x1180 fs/udf/inode.c:622
 inode_getblk fs/udf/inode.c:843 [inline]
 udf_map_block+0xff2/0x45f0 fs/udf/inode.c:454
 __udf_get_block+0x52/0x250 fs/udf/inode.c:468
 __block_write_begin_int+0x6b2/0x1900 fs/buffer.c:2145
 udf_page_mkwrite+0x5be/0x8c0 fs/udf/file.c:65
 do_page_mkwrite+0x14a/0x310 mm/memory.c:3361
 wp_page_shared mm/memory.c:3762 [inline]
 do_wp_page+0x268d/0x5800 mm/memory.c:3981
 handle_pte_fault mm/memory.c:6068 [inline]
 __handle_mm_fault+0x1033/0x5440 mm/memory.c:6195
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364
 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f0aabe55321
Code: 48 8b 54 24 08 48 85 d2 74 17 8b 44 24 18 0f c8 89 c0 48 89 44 24 18 48 83 fa 01 0f 85 b3 01 00 00 48 8b 44 24 10 8b 54 24 18 <89> 10 e9 15 fd ff ff 48 8b 44 24 10 8b 10 48 8b 44 24 08 48 85 c0
RSP: 002b:00007ffd5ccdafa0 EFLAGS: 00010246
RAX: 0000200000514ff8 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000555580a2a3c8
RBP: 00007ffd5ccdb0a8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00007f0aac1e5fac
R13: 00007f0aac1e5fa0 R14: fffffffffffffffe R15: 00007ffd5ccdb0f0
 </TASK>