Zero length message leads to an empty skb
REISERFS panic (device loop7): journal-2332 do_journal_end: Trying to log block 512, which is a log block
------------[ cut here ]------------
kernel BUG at fs/reiserfs/prints.c:390!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4911 Comm: syz.7.94 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __reiserfs_panic+0x150/0x154 fs/reiserfs/prints.c:384
lr : __reiserfs_panic+0x150/0x154 fs/reiserfs/prints.c:384
sp : ffff800020c77560
x29: ffff800020c77620 x28: ffff0000cbbe0678 x27: 0000000000000003
x26: 0000000000000200 x25: 1ffff00003bdb41b x24: ffff800020c775e0
x23: ffff800020c775a0 x22: ffff800011d9f6a0 x21: ffff0000cbbe0000
x20: ffff800011d9f680 x19: ffff8000142990ad x18: 0000000000000001
x17: 0000000000000002 x16: ffff800011b5ac80 x15: 00000000ffffffff
x14: ffff0000cd621b40 x13: 0000000000000001 x12: 0000000000080000
x11: 0000000000019bb3 x10: ffff80002c001000 x9 : 661aaa07ca7af400
x8 : 661aaa07ca7af400 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800020c76cd8 x4 : ffff800014c4fe40 x3 : ffff80000aa1313c
x2 : ffff0001b4173d10 x1 : 0000000100000000 x0 : 0000000000000069
Call trace:
 __reiserfs_panic+0x150/0x154 fs/reiserfs/prints.c:384
 do_journal_end+0x39b0/0x3c50 fs/reiserfs/journal.c:4149
 journal_end_sync fs/reiserfs/journal.c:3535 [inline]
 __commit_trans_jl fs/reiserfs/journal.c:3877 [inline]
 reiserfs_commit_for_inode+0x830/0xb4c fs/reiserfs/journal.c:3920
 reiserfs_sync_file+0x110/0x254 fs/reiserfs/file.c:159
 vfs_fsync_range+0x168/0x188 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2989 [inline]
 generic_file_write_iter+0x15c/0x1b8 mm/filemap.c:3948
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x884/0xb44 fs/read_write.c:594
 ksys_write+0x15c/0x26c fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: f0096205 912700a5 aa1303e4 95c9429c (d4210000) 
---[ end trace 34d776aee858bbe3 ]---