Re: [syzbot] [nvme?] WARNING in nvmet_fc_register_targetport

[Niklas Cassel <cassel@kernel.org>]

On Tue, Aug 11, 2026 at 05:13:24PM -0700, syzbot wrote:
> ------------[ cut here ]------------
> !PageLargeKmalloc(page)
> WARNING: mm/slub.c:6602 at free_large_kmalloc+0xbf/0x100 mm/slub.c:6602, CPU#0: syz.2.261/6867
> Modules linked in:
> CPU: 0 UID: 0 PID: 6867 Comm: syz.2.261 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:free_large_kmalloc+0xbf/0x100 mm/slub.c:6602
> Code: 28 90 0f 0b 90 80 3d e8 ab 9c 0e 00 0f 84 c7 6e b7 fe 48 8b 74 24 28 48 89 ef e8 7c 3a 0c 00 b8 00 f0 ff ff 45 31 ed eb 9d 90 <0f> 0b 90 48 83 c4 08 48 89 df 48 c7 c6 24 df 18 8e 5b 5d 41 5c 41
> RSP: 0018:ffffc9000735fa10 EFLAGS: 00010202
> RAX: 00000000000000ff RBX: ffffea00017e83c0 RCX: 000000000000002e
> RDX: 0000000000000000 RSI: ffff88805fa0ff20 RDI: ffffea00017e83c0
> RBP: ffff88805fa0ff20 R08: ffff888023ddfc00 R09: 00000000ffffffff
> R10: ffffffffffffffff R11: 0000000000000000 R12: 00000000ffffffff
> R13: 1ffff92000e6bf5b R14: dead000000000122 R15: ffff888023ddfc90
> FS:  0000000000000000(0000) GS:ffff888096bf4000(0063) knlGS:00000000f5456b40
> CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
> CR2: 0000000000000000 CR3: 0000000025d36000 CR4: 0000000000352ef0
> Call Trace:
>  <TASK>
>  nvmet_fc_alloc_ls_iodlist drivers/nvme/target/fc.c:569 [inline]
>  nvmet_fc_register_targetport+0x114c/0x1c30 drivers/nvme/target/fc.c:1411
>  fcloop_create_target_port+0x156/0x5a0 drivers/nvme/target/fcloop.c:1558
>  dev_attr_store+0x58/0x80 drivers/base/core.c:2505
>  sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
>  kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
>  new_sync_write fs/read_write.c:595 [inline]
>  vfs_write+0x6ac/0x1050 fs/read_write.c:687
>  ksys_write+0x12a/0x250 fs/read_write.c:739
>  do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
>  __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
>  do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
>  entry_SYSENTER_compat_after_hwframe+0x84/0x8e
> RIP: 0023:0xf7f96fec
> Code: Unable to access opcode bytes at 0xf7f96fc2.
> RSP: 002b:00000000f545650c EFLAGS: 00000292 ORIG_RAX: 0000000000000004
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000200
> RDX: 000000000000002f RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
>  </TASK>
> 
> 
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Fixed by:
https://git.infradead.org/?p=nvme.git;a=commit;h=ba98d6796d12258e837ece065d2ecb59d76ce4ff

queued for nvme-7.3.

#syz fix: nvmet-fc: fix invalid free in LS IOD error path


Kind regards,
Niklas