batman_adv: batadv0: Adding interface: dummy0
batman_adv: batadv0: The MTU of interface dummy0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
batman_adv: batadv0: Interface activated: dummy0
batadv0: mtu less than device minimum
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
netlink: 208452 bytes leftover after parsing attributes in process `syz.0.0'.
------------[ cut here ]------------
le32_to_cpu(aed->lengthAllocDescs) != epos->offset - sizeof(struct allocExtDesc)
WARNING: fs/udf/inode.c:2088 at __udf_add_aext+0x524/0x6d0 fs/udf/inode.c:2087, CPU#0: syz.0.0/5321
Modules linked in:
CPU: 0 UID: 0 PID: 5321 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 04/01/2014
RIP: 0010:__udf_add_aext+0x524/0x6d0 fs/udf/inode.c:2087
Code: a0 dc fe 49 8b 3e 4c 89 e6 e8 68 95 02 ff 31 c0 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d e9 03 5b 5d 08 cc e8 fd ec 70 fe 90 <0f> 0b 90 e9 14 fc ff ff e8 ef ec 70 fe 90 0f 0b 90 e9 66 fd ff ff
RSP: 0018:ffffc9000e1ff7e8 EFLAGS: 00010287
RAX: ffffffff8354ae23 RBX: dffffc0000000000 RCX: 0000000000100000
RDX: ffffc9000ec22000 RSI: 0000000000003e38 RDI: 0000000000003e39
RBP: 1ffff92001c3ff69 R08: ffff888035132480 R09: 0000000000000002
R10: 0000000000000001 R11: 0000000000000002 R12: 00000000000001d0
R13: 0000000000000000 R14: ffffc9000e1ffb40 R15: ffffc9000e1ffb48
FS:  00007f9ce3fcc6c0(0000) GS:ffff88808ca5b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9cd70ffc00 CR3: 0000000033e11000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 udf_setup_indirect_aext+0x609/0x800 fs/udf/inode.c:2050
 udf_add_aext fs/udf/inode.c:2140 [inline]
 udf_do_extend_file+0x8a5/0x11e0 fs/udf/inode.c:591
 udf_extend_file fs/udf/inode.c:712 [inline]
 udf_setsize+0xbf3/0x10b0 fs/udf/inode.c:1300
 udf_setattr+0x3a1/0x5a0 fs/udf/file.c:238
 notify_change+0xc1a/0xf40 fs/attr.c:556
 do_truncate+0x1c2/0x250 fs/open.c:68
 do_ftruncate+0x4db/0x5c0 fs/open.c:196
 do_sys_ftruncate fs/open.c:208 [inline]
 __do_sys_ftruncate fs/open.c:213 [inline]
 __se_sys_ftruncate fs/open.c:211 [inline]
 __x64_sys_ftruncate+0x92/0xf0 fs/open.c:211
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9ce319c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9ce3fcc028 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f9ce3415fa0 RCX: 00007f9ce319c629
RDX: 0000000000000000 RSI: 0000008002007ffb RDI: 000000000000000b
RBP: 00007f9ce3232b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9ce3416038 R14: 00007f9ce3415fa0 R15: 00007fffae8a00d8
 </TASK>