[PATCH v3] nvmet-tcp: reject H2CData before ICReq

[yunje shin]

i agree have been already been fixed by commit
32b63acd78f577b332d976aa06b56e70d054cbba
(nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec)
but i think other thread([PATCH] nvmet-tcp: add bounds checks in
nvmet_tcp_build_pdu_iovec) slab oob is works

On Wed, Jan 28, 2026 at 9:45 AM yunje shin <yjshin0438 at gmail.com> wrote:
>
> Thanks for letting me know. I'll check it.
>
> YunJe
>
>
> On Wed, Jan 28, 2026 at 12:17 AM Maurizio Lombardi
> <mlombard at bsdbackstore.eu> wrote:
> >
> > On Tue Jan 27, 2026 at 3:37 PM CET, Maurizio Lombardi wrote:
> > >
> > > Nevermind, now I get what you mean: you can hit the bug if you send
> > > H2CData after ICReq but before the execution
> > > of the connect command.
> >
> > I was able to reproduce the crash:
> >
> > [25362.399746] BUG: kernel NULL pointer dereference, address: 000000000000000c
> > [25362.403368] #PF: supervisor read access in kernel mode
> > [25362.405451] #PF: error_code(0x0000) - not-present page
> >
> > [...]
> >
> > [25362.430592] Call Trace:
> > [25362.430945]  <TASK>
> > [25362.431250]  ? show_trace_log_lvl+0x1b0/0x2f0
> > [25362.431910]  ? show_trace_log_lvl+0x1b0/0x2f0
> > [25362.432507]  ? nvmet_tcp_done_recv_pdu+0x299/0x2f0 [nvmet_tcp]
> > [25362.433285]  ? __die_body.cold+0x8/0x12
> > [25362.433810]  ? page_fault_oops+0x148/0x160
> > [25362.434388]  ? exc_page_fault+0x73/0x160
> > [25362.434953]  ? asm_exc_page_fault+0x26/0x30
> > [25362.435573]  ? nvmet_tcp_build_pdu_iovec+0x4c/0xc0 [nvmet_tcp]
> > [25362.436357]  nvmet_tcp_done_recv_pdu+0x299/0x2f0 [nvmet_tcp]
> > [25362.437113]  nvmet_tcp_try_recv_pdu+0x1ef/0x2d0 [nvmet_tcp]
> > [25362.437856]  ? sched_balance_update_blocked_averages+0xdd/0x1a0
> > [25362.438672]  nvmet_tcp_io_work+0x70/0x8c0 [nvmet_tcp]
> >
> > But it appears to have been already been fixed by commit 32b63acd78f577b332d976aa06b56e70d054cbba
> > (nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec)
> >
> > dmesg output target-side:
> >
> > [   54.436869] nvmet_tcp: queue 0: H2CData PDU received for invalid command state (ttag 43981)
> >
> >
> > Maurizio