Zero length message leads to an empty skb
loop0: detected capacity change from 0 to 32768
BTRFS: device fsid e417788f-7a09-42b2-9266-8ddc5d5d35d2 devid 1 transid 8 /dev/loop0 (7:0) scanned by syz.0.0 (5349)
BTRFS info (device loop0): first mount of filesystem e417788f-7a09-42b2-9266-8ddc5d5d35d2
BTRFS info (device loop0): using xxhash64 (xxhash64-generic) checksum algorithm
BTRFS info (device loop0): using free-space-tree
BTRFS info (device loop0): balance: start -susage=5,drange=7..526332,limit=0..6
------------[ cut here ]------------
BTRFS: Transaction aborted (error -28)
WARNING: CPU: 0 PID: 5349 at fs/btrfs/block-group.c:2781 btrfs_create_pending_block_groups+0x1120/0x1360 fs/btrfs/block-group.c:2781
Modules linked in:
CPU: 0 UID: 0 PID: 5349 Comm: syz.0.0 Not tainted 6.16.0-rc5-syzkaller-00266-g3f31a806a62e #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:btrfs_create_pending_block_groups+0x1120/0x1360 fs/btrfs/block-group.c:2781
Code: 48 c7 c6 80 bf cf 8b 44 89 f2 e8 eb 6b 42 fd e9 38 fe ff ff e8 51 78 d8 fd 90 48 c7 c7 20 bf cf 8b 44 89 f6 e8 11 5b 9c fd 90 <0f> 0b 90 90 e9 19 fe ff ff e8 32 78 d8 fd eb 05 e8 2b 78 d8 fd 4c
RSP: 0018:ffffc9000d51f6e0 EFLAGS: 00010246
RAX: 53d632f86c81dd00 RBX: ffff88805389c001 RCX: 0000000000100000
RDX: ffffc9000e3ca000 RSI: 000000000000a594 RDI: 000000000000a595
RBP: ffffc9000d51f958 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfaa64 R12: 0000000000000000
R13: dffffc0000000000 R14: 00000000ffffffe4 R15: ffff888012363858
FS:  00007fd4597816c0(0000) GS:ffff88808d21b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4c256e2080 CR3: 000000004293a000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __btrfs_end_transaction+0x140/0x640 fs/btrfs/transaction.c:1071
 btrfs_inc_block_group_ro+0x641/0x6f0 fs/btrfs/block-group.c:3077
 btrfs_relocate_block_group+0x47a/0xde0 fs/btrfs/relocation.c:3962
 btrfs_relocate_chunk+0x12a/0x3b0 fs/btrfs/volumes.c:3437
 __btrfs_balance+0x1870/0x21d0 fs/btrfs/volumes.c:4212
 btrfs_balance+0xc94/0x11d0 fs/btrfs/volumes.c:4589
 btrfs_ioctl_balance+0x3d3/0x610 fs/btrfs/ioctl.c:3583
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd45898e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd459781038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd458bb5fa0 RCX: 00007fd45898e929
RDX: 0000200000000440 RSI: 00000000c4009420 RDI: 0000000000000006
RBP: 00007fd458a10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd458bb5fa0 R15: 00007ffc6f4eb998
 </TASK>